diff --git a/.editorconfig b/.editorconfig
index 639cce3aa0..0a6cd765d8 100644
--- a/.editorconfig
+++ b/.editorconfig
@@ -7,5 +7,8 @@ end_of_line = lf
 insert_final_newline = true
 trim_trailing_whitespace = true
 
-[*.md,*.snap]
+[*.md]
+trim_trailing_whitespace = false
+
+[*.snap]
 trim_trailing_whitespace = false
diff --git a/.gitignore b/.gitignore
index 6bf7fdc08f..bc66b30bc2 100644
--- a/.gitignore
+++ b/.gitignore
@@ -43,13 +43,14 @@ jspm_packages
 
 .vscode
 .idea
-
+.cache
 
 # tests specific
 tests/simple-long-path/long-src-path
 # is linked to the temp dir of the os
 e2e/__workdir_synlink__
 **/.ts-jest-e2e.json
+.ts-jest-digest
 # while refactoring...
 old/
 
diff --git a/.npmignore b/.npmignore
index 9168b0e8cf..807d8ccce6 100644
--- a/.npmignore
+++ b/.npmignore
@@ -69,8 +69,12 @@ tsconfig.build.json
 tslint.json
 .npmrc
 .markdownlint.yaml
+.cache
 
 # Github Pages
 docs
 
 commitlint.config.js
+
+# ensure we do not omit the digest
+!.ts-jest-digest
diff --git a/.travis.yml b/.travis.yml
index ebc1a548a3..40686a9023 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -6,6 +6,7 @@ env:
 cache:
   npm: true
   directories:
+    - .cache
     - /tmp/ts-jest-e2e-workdir/__templates__
 
 node_js:
@@ -36,9 +37,9 @@ script:
   # only grab coverage data on node 10
   - |
       if [[ "$(node --version)" == v10.* ]]; then
-        npm run test -- --coverage;
+        npm run test -- --runInBand --coverage;
       else
-        npm run test;
+        npm run test -- --runInBand;
       fi
 
 after_success:
diff --git a/appveyor.yml b/appveyor.yml
index adc381521a..7610f4e0f9 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -21,19 +21,20 @@ install:
   - ps: Install-Product node 8 x64
   - npm install -g npm@^5
   # Typical npm stuff.
-  - set CI=true
+  # - set CI=true
   # Our E2E work dir
   - set TS_JEST_E2E_WORKDIR=%APPDATA%\ts-jest-e2e
   - npm ci --ignore-scripts
   - npm run clean -- --when-ci-commit-message
 
 cache:
+  - .cache -> package.json
   - '%APPDATA%\npm-cache'
   - '%APPDATA%\ts-jest-e2e\__templates__'
 
 # Post-install test scripts.
 test_script:
-  - cmd: npm run test
+  - cmd: npm run test -- --runInBand
 
 # skip_commits:
 #   files:
diff --git a/e2e/__cases__/deep/src/Tests/jest.config.js b/e2e/__cases__/deep/src/Tests/jest.config.js
index 3ad00da01c..5f8f09a3cc 100755
--- a/e2e/__cases__/deep/src/Tests/jest.config.js
+++ b/e2e/__cases__/deep/src/Tests/jest.config.js
@@ -20,5 +20,4 @@ module.exports = Object.assign({}, cfg, {
       tsConfig: "./tsconfig.json",
     },
   },
-  // testResultsProcessor: "jest-teamcity-reporter",
 })
diff --git a/e2e/__cases__/ts-jest-checks/index.spec.ts b/e2e/__cases__/ts-jest-checks/index.spec.ts
new file mode 100644
index 0000000000..2ea1f32ce1
--- /dev/null
+++ b/e2e/__cases__/ts-jest-checks/index.spec.ts
@@ -0,0 +1,12 @@
+import { createTransformer } from 'ts-jest'
+import { readFileSync } from 'fs'
+
+describe('tsConfig', () => {
+  it('should have digest and versions', () => {
+    const tr = createTransformer()
+    const cs = tr.configsFor({} as any)
+    expect(cs.tsJestDigest).toHaveLength(40)
+    expect(cs.tsJestDigest).toBe(readFileSync(require.resolve('ts-jest/.ts-jest-digest'), 'utf8'))
+    expect(cs.versions['ts-jest']).toBe(require('ts-jest/package.json').version)
+  })
+})
diff --git a/e2e/__helpers__/test-case/run-result.ts b/e2e/__helpers__/test-case/run-result.ts
index f37ec02a08..ca80a640e5 100644
--- a/e2e/__helpers__/test-case/run-result.ts
+++ b/e2e/__helpers__/test-case/run-result.ts
@@ -4,6 +4,8 @@ import { readFileSync, realpathSync } from 'fs'
 import { tmpdir } from 'os'
 import { resolve, sep } from 'path'
 
+import { cacheDir } from '../../../scripts/lib/paths'
+
 import ProcessedFileIo from './processed-file-io'
 import { escapeRegex, normalizeJestOutput, stripAnsiColors } from './utils'
 
@@ -17,6 +19,7 @@ export default class RunResult {
       cmd: string
       args: string[]
       env: { [key: string]: string }
+      config: jest.InitialOptions
     }>,
   ) {}
   get logFilePath() {
@@ -56,9 +59,11 @@ export default class RunResult {
     return normalizeJestOutput(this.stdout)
   }
   get cmdLine() {
-    return [this.context.cmd, ...this.context.args]
-      .filter(a => !['-u', '--updateSnapshot', '--runInBand', '--'].includes(a))
-      .join(' ')
+    return this.normalize(
+      [this.context.cmd, ...this.context.args]
+        .filter(a => !['-u', '--updateSnapshot', '--runInBand', '--'].includes(a))
+        .join(' '),
+    )
   }
 
   ioFor(relFilePath: string): ProcessedFileIo {
@@ -80,7 +85,12 @@ export default class RunResult {
     const realCwd = realpathSync(cwd)
     const tmp = tmpdir()
     const realTmp = realpathSync(tmp)
-    const map = [{ from: cwd, to: '<cwd>' }, { from: tmp, to: '<tmp>' }, { from: /\b[a-f0-9]{40}\b/g, to: '<hex:40>' }]
+    const map = [
+      { from: cwd, to: '<cwd>' },
+      { from: tmp, to: '<tmp>' },
+      { from: /\b[a-f0-9]{40}\b/g, to: '<hex:40>' },
+      { from: cacheDir, to: '<ts-jest-cache>' },
+    ]
     if (cwd !== realCwd) map.push({ from: realCwd, to: '<cwd>' })
     if (tmp !== realTmp) map.push({ from: realTmp, to: '<tmp>' })
     if (sep === '\\') {
diff --git a/e2e/__helpers__/test-case/runtime.ts b/e2e/__helpers__/test-case/runtime.ts
index b31ce8bf9f..c4eb2b5684 100644
--- a/e2e/__helpers__/test-case/runtime.ts
+++ b/e2e/__helpers__/test-case/runtime.ts
@@ -16,7 +16,7 @@ import {
   writeFileSync,
 } from 'fs-extra'
 import merge from 'lodash.merge'
-import { join, relative, sep } from 'path'
+import { join, relative, resolve, sep } from 'path'
 
 import * as Paths from '../../../scripts/lib/paths'
 
@@ -49,19 +49,35 @@ function hooksSourceWith(vars: Record<string, any>): string {
 }
 
 export function run(name: string, options: RunTestOptions = {}): RunResult {
-  const { args = [], env = {}, template, inject, writeIo } = options
+  const {
+    args = [],
+    env = {},
+    template,
+    inject,
+    writeIo,
+    noCache,
+    jestConfigPath: configFile = 'jest.config.js',
+  } = options
   const { workdir: dir, sourceDir, hooksFile, ioDir } = prepareTest(
     name,
     template || templateNameForPath(join(Paths.e2eSourceDir, name)),
     options,
   )
-  const pkg = require(join(dir, 'package.json'))
+  const pkg = readJsonSync(join(dir, 'package.json'))
+
+  // grab base configuration
+  const jestConfigPath = resolve(dir, configFile)
+  let baseConfig: jest.InitialOptions = require(jestConfigPath)
+  if (configFile === 'package.json') baseConfig = (baseConfig as any).jest
+
+  const extraConfig = {} as jest.InitialOptions
 
   let shortCmd: string
   let cmdArgs: string[] = []
   if (inject) {
-    cmdArgs.push('--testPathPattern="/__eval\\\\.ts$"')
-  } // '--testRegex=""'
+    extraConfig.testMatch = undefined
+    extraConfig.testRegex = '/__eval\\.ts$'
+  }
   if (process.argv.find(v => ['--updateSnapshot', '-u'].includes(v))) {
     cmdArgs.push('-u')
   }
@@ -77,25 +93,42 @@ export function run(name: string, options: RunTestOptions = {}): RunResult {
     shortCmd = 'jest'
   }
 
-  // merge given config extend
-  if (options.jestConfig || options.tsJestConfig) {
-    let originalConfig: any = join(dir, 'jest.config.js')
-    if (existsSync(originalConfig)) {
-      originalConfig = require(originalConfig)
+  // check/merge config
+  if (cmdArgs.includes('--config')) {
+    throw new Error(`Extend config using tsJestConfig and jestConfig options, not thru args.`)
+  }
+  if (cmdArgs.includes('--no-cache')) {
+    throw new Error(`Use the noCache option to disable cache, not thru args.`)
+  }
+  // extends config
+  if (options.jestConfig) {
+    merge(extraConfig, options.jestConfig)
+  }
+  if (options.tsJestConfig) {
+    const globalConfig: any = extraConfig.globals || (extraConfig.globals = {})
+    const tsJestConfig = globalConfig['ts-jest'] || (globalConfig['ts-jest'] = {})
+    merge(tsJestConfig, options.tsJestConfig)
+  }
+
+  if (noCache || writeIo) {
+    cmdArgs.push('--no-cache')
+  } else if (!(baseConfig.cacheDirectory || extraConfig.cacheDirectory)) {
+    // force the cache directory if not set
+    extraConfig.cacheDirectory = join(Paths.cacheDir, `e2e-${template}`)
+  }
+
+  // write final config
+  const finalConfig = merge({}, baseConfig, extraConfig)
+  if (Object.keys(extraConfig).length !== 0) {
+    if (configFile === 'package.json') {
+      pkg.jest = finalConfig
+      outputJsonSync(jestConfigPath, pkg)
     } else {
-      originalConfig = require(join(dir, 'package.json')).jest || {}
+      outputFileSync(jestConfigPath, `module.exports = ${JSON.stringify(finalConfig, null, 2)}`, 'utf8')
     }
-    cmdArgs.push(
-      '--config',
-      JSON.stringify(
-        merge({}, originalConfig, options.jestConfig, {
-          globals: { 'ts-jest': options.tsJestConfig || {} },
-        }),
-      ),
-    )
   }
 
-  // run in band
+  // ensure we run in band
   if (!cmdArgs.includes('--runInBand')) {
     cmdArgs.push('--runInBand')
   }
@@ -142,6 +175,7 @@ export function run(name: string, options: RunTestOptions = {}): RunResult {
     args: cmdArgs,
     env: mergedEnv,
     ioDir: writeIo ? ioDir : undefined,
+    config: finalConfig,
   })
 }
 
diff --git a/e2e/__helpers__/test-case/types.ts b/e2e/__helpers__/test-case/types.ts
index 3bba78e2f5..3df848b707 100644
--- a/e2e/__helpers__/test-case/types.ts
+++ b/e2e/__helpers__/test-case/types.ts
@@ -10,6 +10,8 @@ export interface RunTestOptions {
   writeIo?: boolean
   jestConfig?: jest.ProjectConfig | any
   tsJestConfig?: TsJestConfig | any
+  noCache?: boolean
+  jestConfigPath?: string
 }
 
 export type RunWithTemplatesIterator = (runtTest: () => RunResult, context: RunWithTemplateIteratorContext) => void
diff --git a/e2e/__tests__/__snapshots__/diagnostics.test.ts.snap b/e2e/__tests__/__snapshots__/diagnostics.test.ts.snap
index 9f64c55c43..7be8b505c4 100644
--- a/e2e/__tests__/__snapshots__/diagnostics.test.ts.snap
+++ b/e2e/__tests__/__snapshots__/diagnostics.test.ts.snap
@@ -116,7 +116,7 @@ exports[`With diagnostics, first throws should fail using template "with-typescr
 `;
 
 exports[`With diagnostics, warn only should pass using template "default" 1`] = `
-  √ jest --config {"preset":"ts-jest","testEnvironment":"node","globals":{"ts-jest":{"tsConfig":{},"diagnostics":{"warnOnly":true}}}}
+  √ jest --no-cache
   ↳ exit code: 0
   ===[ STDOUT ]===================================================================
   
@@ -138,7 +138,7 @@ exports[`With diagnostics, warn only should pass using template "default" 1`] =
 `;
 
 exports[`With diagnostics, warn only should pass using template "with-babel-6" 1`] = `
-  √ jest --config {"preset":"ts-jest","testEnvironment":"node","globals":{"ts-jest":{"tsConfig":{},"babelConfig":true,"diagnostics":{"warnOnly":true}}}}
+  √ jest --no-cache
   ↳ exit code: 0
   ===[ STDOUT ]===================================================================
   
@@ -160,7 +160,7 @@ exports[`With diagnostics, warn only should pass using template "with-babel-6" 1
 `;
 
 exports[`With diagnostics, warn only should pass using template "with-babel-7" 1`] = `
-  √ jest --config {"preset":"ts-jest","testEnvironment":"node","globals":{"ts-jest":{"tsConfig":{},"babelConfig":true,"diagnostics":{"warnOnly":true}}}}
+  √ jest --no-cache
   ↳ exit code: 0
   ===[ STDOUT ]===================================================================
   
@@ -182,7 +182,7 @@ exports[`With diagnostics, warn only should pass using template "with-babel-7" 1
 `;
 
 exports[`With diagnostics, warn only should pass using template "with-jest-22" 1`] = `
-  √ jest --config {"transform":{"^.+\\\\.tsx?$":"ts-jest"},"testMatch":["**/__tests__/**/*.js?(x)","**/?(*.)+(spec|test).js?(x)","**/__tests__/**/*.ts?(x)","**/?(*.)+(spec|test).ts?(x)"],"moduleFileExtensions":["js","json","jsx","node","ts","tsx"],"testEnvironment":"node","globals":{"ts-jest":{"tsConfig":{},"diagnostics":{"warnOnly":true}}}}
+  √ jest --no-cache
   ↳ exit code: 0
   ===[ STDOUT ]===================================================================
   
@@ -204,7 +204,7 @@ exports[`With diagnostics, warn only should pass using template "with-jest-22" 1
 `;
 
 exports[`With diagnostics, warn only should pass using template "with-typescript-2-7" 1`] = `
-  √ jest --config {"preset":"ts-jest","testEnvironment":"node","globals":{"ts-jest":{"tsConfig":{},"diagnostics":{"ignoreCodes":[5023],"warnOnly":true}}}}
+  √ jest --no-cache
   ↳ exit code: 0
   ===[ STDOUT ]===================================================================
   
diff --git a/e2e/__tests__/__snapshots__/hoisting.test.ts.snap b/e2e/__tests__/__snapshots__/hoisting.test.ts.snap
index 7c4099282b..fcbf5639d3 100644
--- a/e2e/__tests__/__snapshots__/hoisting.test.ts.snap
+++ b/e2e/__tests__/__snapshots__/hoisting.test.ts.snap
@@ -58,7 +58,7 @@ exports[`Hoisting jest.mock() & jest.unmock() should pass using template "defaul
 `;
 
 exports[`Hoisting jest.mock() & jest.unmock() should pass using template "default": output 1`] = `
-  √ jest
+  √ jest --no-cache
   ↳ exit code: 0
   ===[ STDOUT ]===================================================================
   
@@ -134,7 +134,7 @@ exports[`Hoisting jest.mock() & jest.unmock() should pass using template "with-b
 `;
 
 exports[`Hoisting jest.mock() & jest.unmock() should pass using template "with-babel-6": output 1`] = `
-  √ jest
+  √ jest --no-cache
   ↳ exit code: 0
   ===[ STDOUT ]===================================================================
   
@@ -218,7 +218,7 @@ exports[`Hoisting jest.mock() & jest.unmock() should pass using template "with-b
 `;
 
 exports[`Hoisting jest.mock() & jest.unmock() should pass using template "with-babel-7": output 1`] = `
-  √ jest
+  √ jest --no-cache
   ↳ exit code: 0
   ===[ STDOUT ]===================================================================
   
@@ -293,7 +293,7 @@ exports[`Hoisting jest.mock() & jest.unmock() should pass using template "with-j
 `;
 
 exports[`Hoisting jest.mock() & jest.unmock() should pass using template "with-jest-22": output 1`] = `
-  √ jest
+  √ jest --no-cache
   ↳ exit code: 0
   ===[ STDOUT ]===================================================================
   
@@ -368,7 +368,7 @@ exports[`Hoisting jest.mock() & jest.unmock() should pass using template "with-t
 `;
 
 exports[`Hoisting jest.mock() & jest.unmock() should pass using template "with-typescript-2-7": output 1`] = `
-  √ jest
+  √ jest --no-cache
   ↳ exit code: 0
   ===[ STDOUT ]===================================================================
   
diff --git a/e2e/__tests__/__snapshots__/isolated-modules.test.ts.snap b/e2e/__tests__/__snapshots__/isolated-modules.test.ts.snap
index ae5954b391..f744686504 100644
--- a/e2e/__tests__/__snapshots__/isolated-modules.test.ts.snap
+++ b/e2e/__tests__/__snapshots__/isolated-modules.test.ts.snap
@@ -1,7 +1,7 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
 exports[`With isolatedModules enabled should pass using template "default" 1`] = `
-  √ jest --config {"preset":"ts-jest","testEnvironment":"node","globals":{"ts-jest":{"tsConfig":{},"isolatedModules":true}}}
+  √ jest
   ↳ exit code: 0
   ===[ STDOUT ]===================================================================
   
@@ -18,7 +18,7 @@ exports[`With isolatedModules enabled should pass using template "default" 1`] =
 `;
 
 exports[`With isolatedModules enabled should pass using template "with-babel-6" 1`] = `
-  √ jest --config {"preset":"ts-jest","testEnvironment":"node","globals":{"ts-jest":{"tsConfig":{},"babelConfig":true,"isolatedModules":true}}}
+  √ jest
   ↳ exit code: 0
   ===[ STDOUT ]===================================================================
   
@@ -35,7 +35,7 @@ exports[`With isolatedModules enabled should pass using template "with-babel-6"
 `;
 
 exports[`With isolatedModules enabled should pass using template "with-babel-7" 1`] = `
-  √ jest --config {"preset":"ts-jest","testEnvironment":"node","globals":{"ts-jest":{"tsConfig":{},"babelConfig":true,"isolatedModules":true}}}
+  √ jest
   ↳ exit code: 0
   ===[ STDOUT ]===================================================================
   
@@ -52,7 +52,7 @@ exports[`With isolatedModules enabled should pass using template "with-babel-7"
 `;
 
 exports[`With isolatedModules enabled should pass using template "with-jest-22" 1`] = `
-  √ jest --config {"transform":{"^.+\\\\.tsx?$":"ts-jest"},"testMatch":["**/__tests__/**/*.js?(x)","**/?(*.)+(spec|test).js?(x)","**/__tests__/**/*.ts?(x)","**/?(*.)+(spec|test).ts?(x)"],"moduleFileExtensions":["js","json","jsx","node","ts","tsx"],"testEnvironment":"node","globals":{"ts-jest":{"tsConfig":{},"isolatedModules":true}}}
+  √ jest
   ↳ exit code: 0
   ===[ STDOUT ]===================================================================
   
@@ -69,7 +69,7 @@ exports[`With isolatedModules enabled should pass using template "with-jest-22"
 `;
 
 exports[`With isolatedModules enabled should pass using template "with-typescript-2-7" 1`] = `
-  √ jest --config {"preset":"ts-jest","testEnvironment":"node","globals":{"ts-jest":{"tsConfig":{},"diagnostics":{"ignoreCodes":[5023]},"isolatedModules":true}}}
+  √ jest
   ↳ exit code: 0
   ===[ STDOUT ]===================================================================
   
diff --git a/e2e/__tests__/__snapshots__/logger.test.ts.snap b/e2e/__tests__/__snapshots__/logger.test.ts.snap
index 5cf91db511..97c29db22f 100644
--- a/e2e/__tests__/__snapshots__/logger.test.ts.snap
+++ b/e2e/__tests__/__snapshots__/logger.test.ts.snap
@@ -1,6 +1,6 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`TS_JEST_LOG should pass and create log file when using tempalte "default" 1`] = `
+exports[`TS_JEST_LOG should pass and create log file when using template "default" 1`] = `
 Array [
   "[level:20] creating jest presets not handling JavaScript files",
   "[level:20] creating Importer singleton",
@@ -20,26 +20,24 @@ Array [
   "[level:20] normalized typescript config",
   "[level:20] processing <cwd>/Hello.spec.ts",
   "[level:20] creating typescript compiler (language service)",
-  "[level:20] will use file caching",
+  "[level:20] file caching disabled",
   "[level:20] creating language service",
-  "[level:20] readThrough(): cache miss",
+  "[level:20] readThrough(): no cache",
   "[level:20] getOutput(): compiling using language service",
   "[level:20] updateMemoryCache()",
   "[level:20] visitSourceFileNode(): hoisting",
   "[level:20] getOutput(): computing diagnostics",
-  "[level:20] readThrough(): writing caches",
   "[level:20] computing cache key for <cwd>/Hello.ts",
   "[level:20] processing <cwd>/Hello.ts",
-  "[level:20] readThrough(): cache miss",
+  "[level:20] readThrough(): no cache",
   "[level:20] getOutput(): compiling using language service",
   "[level:20] updateMemoryCache()",
   "[level:20] visitSourceFileNode(): hoisting",
   "[level:20] getOutput(): computing diagnostics",
-  "[level:20] readThrough(): writing caches",
 ]
 `;
 
-exports[`TS_JEST_LOG should pass and create log file when using tempalte "with-babel-6" 1`] = `
+exports[`TS_JEST_LOG should pass and create log file when using template "with-babel-6" 1`] = `
 Array [
   "[level:20] creating jest presets not handling JavaScript files",
   "[level:20] creating Importer singleton",
@@ -68,28 +66,26 @@ Array [
   "[level:20] patching babel-jest",
   "[level:20] checking version of babel-jest: OK",
   "[level:20] creating typescript compiler (language service)",
-  "[level:20] will use file caching",
+  "[level:20] file caching disabled",
   "[level:20] creating language service",
-  "[level:20] readThrough(): cache miss",
+  "[level:20] readThrough(): no cache",
   "[level:20] getOutput(): compiling using language service",
   "[level:20] updateMemoryCache()",
   "[level:20] visitSourceFileNode(): hoisting",
   "[level:20] getOutput(): computing diagnostics",
-  "[level:20] readThrough(): writing caches",
   "[level:20] calling babel-jest processor",
   "[level:20] computing cache key for <cwd>/Hello.ts",
   "[level:20] processing <cwd>/Hello.ts",
-  "[level:20] readThrough(): cache miss",
+  "[level:20] readThrough(): no cache",
   "[level:20] getOutput(): compiling using language service",
   "[level:20] updateMemoryCache()",
   "[level:20] visitSourceFileNode(): hoisting",
   "[level:20] getOutput(): computing diagnostics",
-  "[level:20] readThrough(): writing caches",
   "[level:20] calling babel-jest processor",
 ]
 `;
 
-exports[`TS_JEST_LOG should pass and create log file when using tempalte "with-babel-7" 1`] = `
+exports[`TS_JEST_LOG should pass and create log file when using template "with-babel-7" 1`] = `
 Array [
   "[level:20] creating jest presets not handling JavaScript files",
   "[level:20] creating Importer singleton",
@@ -117,28 +113,26 @@ Array [
   "[level:20] patching babel-jest",
   "[level:20] checking version of babel-jest: OK",
   "[level:20] creating typescript compiler (language service)",
-  "[level:20] will use file caching",
+  "[level:20] file caching disabled",
   "[level:20] creating language service",
-  "[level:20] readThrough(): cache miss",
+  "[level:20] readThrough(): no cache",
   "[level:20] getOutput(): compiling using language service",
   "[level:20] updateMemoryCache()",
   "[level:20] visitSourceFileNode(): hoisting",
   "[level:20] getOutput(): computing diagnostics",
-  "[level:20] readThrough(): writing caches",
   "[level:20] calling babel-jest processor",
   "[level:20] computing cache key for <cwd>/Hello.ts",
   "[level:20] processing <cwd>/Hello.ts",
-  "[level:20] readThrough(): cache miss",
+  "[level:20] readThrough(): no cache",
   "[level:20] getOutput(): compiling using language service",
   "[level:20] updateMemoryCache()",
   "[level:20] visitSourceFileNode(): hoisting",
   "[level:20] getOutput(): computing diagnostics",
-  "[level:20] readThrough(): writing caches",
   "[level:20] calling babel-jest processor",
 ]
 `;
 
-exports[`TS_JEST_LOG should pass and create log file when using tempalte "with-jest-22" 1`] = `
+exports[`TS_JEST_LOG should pass and create log file when using template "with-jest-22" 1`] = `
 Array [
   "[level:20] creating Importer singleton",
   "[level:20] creating jest presets not handling JavaScript files",
@@ -157,26 +151,24 @@ Array [
   "[level:20] normalized typescript config",
   "[level:20] processing <cwd>/Hello.spec.ts",
   "[level:20] creating typescript compiler (language service)",
-  "[level:20] will use file caching",
+  "[level:20] file caching disabled",
   "[level:20] creating language service",
-  "[level:20] readThrough(): cache miss",
+  "[level:20] readThrough(): no cache",
   "[level:20] getOutput(): compiling using language service",
   "[level:20] updateMemoryCache()",
   "[level:20] visitSourceFileNode(): hoisting",
   "[level:20] getOutput(): computing diagnostics",
-  "[level:20] readThrough(): writing caches",
   "[level:20] computing cache key for <cwd>/Hello.ts",
   "[level:20] processing <cwd>/Hello.ts",
-  "[level:20] readThrough(): cache miss",
+  "[level:20] readThrough(): no cache",
   "[level:20] getOutput(): compiling using language service",
   "[level:20] updateMemoryCache()",
   "[level:20] visitSourceFileNode(): hoisting",
   "[level:20] getOutput(): computing diagnostics",
-  "[level:20] readThrough(): writing caches",
 ]
 `;
 
-exports[`TS_JEST_LOG should pass and create log file when using tempalte "with-typescript-2-7" 1`] = `
+exports[`TS_JEST_LOG should pass and create log file when using template "with-typescript-2-7" 1`] = `
 Array [
   "[level:20] creating jest presets not handling JavaScript files",
   "[level:20] creating Importer singleton",
@@ -196,22 +188,20 @@ Array [
   "[level:20] normalized typescript config",
   "[level:20] processing <cwd>/Hello.spec.ts",
   "[level:20] creating typescript compiler (language service)",
-  "[level:20] will use file caching",
+  "[level:20] file caching disabled",
   "[level:20] creating language service",
-  "[level:20] readThrough(): cache miss",
+  "[level:20] readThrough(): no cache",
   "[level:20] getOutput(): compiling using language service",
   "[level:20] updateMemoryCache()",
   "[level:20] visitSourceFileNode(): hoisting",
   "[level:20] getOutput(): computing diagnostics",
-  "[level:20] readThrough(): writing caches",
   "[level:20] computing cache key for <cwd>/Hello.ts",
   "[level:20] processing <cwd>/Hello.ts",
-  "[level:20] readThrough(): cache miss",
+  "[level:20] readThrough(): no cache",
   "[level:20] getOutput(): compiling using language service",
   "[level:20] updateMemoryCache()",
   "[level:20] visitSourceFileNode(): hoisting",
   "[level:20] getOutput(): computing diagnostics",
-  "[level:20] readThrough(): writing caches",
 ]
 `;
 
diff --git a/e2e/__tests__/__snapshots__/simple.test.ts.snap b/e2e/__tests__/__snapshots__/simple.test.ts.snap
deleted file mode 100644
index 94d0438d92..0000000000
--- a/e2e/__tests__/__snapshots__/simple.test.ts.snap
+++ /dev/null
@@ -1,91 +0,0 @@
-// Jest Snapshot v1, https://goo.gl/fbAQLP
-
-exports[`Simple test should pass using template "default" 1`] = `
-  √ jest
-  ↳ exit code: 0
-  ===[ STDOUT ]===================================================================
-  
-  ===[ STDERR ]===================================================================
-  PASS ./Hello.spec.ts
-    Hello Class
-      √ should create a new Hello
-  
-  Test Suites: 1 passed, 1 total
-  Tests:       1 passed, 1 total
-  Snapshots:   0 total
-  Time:        XXs
-  Ran all test suites.
-  ================================================================================
-`;
-
-exports[`Simple test should pass using template "with-babel-6" 1`] = `
-  √ jest
-  ↳ exit code: 0
-  ===[ STDOUT ]===================================================================
-  
-  ===[ STDERR ]===================================================================
-  PASS ./Hello.spec.ts
-    Hello Class
-      √ should create a new Hello
-  
-  Test Suites: 1 passed, 1 total
-  Tests:       1 passed, 1 total
-  Snapshots:   0 total
-  Time:        XXs
-  Ran all test suites.
-  ================================================================================
-`;
-
-exports[`Simple test should pass using template "with-babel-7" 1`] = `
-  √ jest
-  ↳ exit code: 0
-  ===[ STDOUT ]===================================================================
-  
-  ===[ STDERR ]===================================================================
-  PASS ./Hello.spec.ts
-    Hello Class
-      √ should create a new Hello
-  
-  Test Suites: 1 passed, 1 total
-  Tests:       1 passed, 1 total
-  Snapshots:   0 total
-  Time:        XXs
-  Ran all test suites.
-  ================================================================================
-`;
-
-exports[`Simple test should pass using template "with-jest-22" 1`] = `
-  √ jest
-  ↳ exit code: 0
-  ===[ STDOUT ]===================================================================
-  
-  ===[ STDERR ]===================================================================
-  PASS ./Hello.spec.ts
-    Hello Class
-      √ should create a new Hello
-  
-  Test Suites: 1 passed, 1 total
-  Tests:       1 passed, 1 total
-  Snapshots:   0 total
-  Time:        XXs
-  Ran all test suites.
-  ================================================================================
-`;
-
-exports[`Simple test should pass using template "with-typescript-2-7" 1`] = `
-  √ jest
-  ↳ exit code: 0
-  ===[ STDOUT ]===================================================================
-  
-  ===[ STDERR ]===================================================================
-  PASS ./Hello.spec.ts
-    Hello Class
-      √ should create a new Hello
-  
-  Test Suites: 1 passed, 1 total
-  Tests:       1 passed, 1 total
-  Snapshots:   0 total
-  Time:        XXs
-  Ran all test suites.
-  ================================================================================
-`;
diff --git a/e2e/__tests__/__snapshots__/source-map.test.ts.snap b/e2e/__tests__/__snapshots__/source-map.test.ts.snap
index d599ee72ce..4f10c0e99d 100644
--- a/e2e/__tests__/__snapshots__/source-map.test.ts.snap
+++ b/e2e/__tests__/__snapshots__/source-map.test.ts.snap
@@ -34,7 +34,7 @@ exports[`using template "default" should have the source maps comment 1`] = `
 `;
 
 exports[`using template "default" should report correct line numbers 1`] = `
-  × jest --config {"preset":"ts-jest","testEnvironment":"node","globals":{"ts-jest":{"tsConfig":{},"diagnostics":{"ignoreCodes":[5023,7027]}}}}
+  × jest --no-cache
   ↳ exit code: 1
   ===[ STDOUT ]===================================================================
   console.log main.ts:2
@@ -121,7 +121,7 @@ exports[`using template "with-babel-6" should have the source maps comment 1`] =
 `;
 
 exports[`using template "with-babel-6" should report correct line numbers 1`] = `
-  × jest --config {"preset":"ts-jest","testEnvironment":"node","globals":{"ts-jest":{"tsConfig":{},"babelConfig":true,"diagnostics":{"ignoreCodes":[5023,7027]}}}}
+  × jest --no-cache
   ↳ exit code: 1
   ===[ STDOUT ]===================================================================
   console.log main.ts:2
@@ -214,7 +214,7 @@ exports[`using template "with-babel-7" should have the source maps comment 1`] =
 `;
 
 exports[`using template "with-babel-7" should report correct line numbers 1`] = `
-  × jest --config {"preset":"ts-jest","testEnvironment":"node","globals":{"ts-jest":{"tsConfig":{},"babelConfig":true,"diagnostics":{"ignoreCodes":[5023,7027]}}}}
+  × jest --no-cache
   ↳ exit code: 1
   ===[ STDOUT ]===================================================================
   console.log main.ts:2
@@ -301,7 +301,7 @@ exports[`using template "with-jest-22" should have the source maps comment 1`] =
 `;
 
 exports[`using template "with-jest-22" should report correct line numbers 1`] = `
-  × jest --config {"transform":{"^.+\\\\.tsx?$":"ts-jest"},"testMatch":["**/__tests__/**/*.js?(x)","**/?(*.)+(spec|test).js?(x)","**/__tests__/**/*.ts?(x)","**/?(*.)+(spec|test).ts?(x)"],"moduleFileExtensions":["js","json","jsx","node","ts","tsx"],"testEnvironment":"node","globals":{"ts-jest":{"tsConfig":{},"diagnostics":{"ignoreCodes":[5023,7027]}}}}
+  × jest --no-cache
   ↳ exit code: 1
   ===[ STDOUT ]===================================================================
   console.log main.ts:2
@@ -386,7 +386,7 @@ exports[`using template "with-typescript-2-7" should have the source maps commen
 `;
 
 exports[`using template "with-typescript-2-7" should report correct line numbers 1`] = `
-  × jest --config {"preset":"ts-jest","testEnvironment":"node","globals":{"ts-jest":{"tsConfig":{},"diagnostics":{"ignoreCodes":[5023,7027]}}}}
+  × jest --no-cache
   ↳ exit code: 1
   ===[ STDOUT ]===================================================================
   console.log main.ts:2
diff --git a/e2e/__tests__/diagnostics.test.ts b/e2e/__tests__/diagnostics.test.ts
index a477d929d7..a118b33e6a 100644
--- a/e2e/__tests__/diagnostics.test.ts
+++ b/e2e/__tests__/diagnostics.test.ts
@@ -14,7 +14,10 @@ describe('With diagnostics, first throws', () => {
 })
 
 describe('With diagnostics, warn only', () => {
-  const testCase = configureTestCase('diagnostics', { tsJestConfig: { diagnostics: { warnOnly: true } } })
+  const testCase = configureTestCase('diagnostics', {
+    tsJestConfig: { diagnostics: { warnOnly: true } },
+    noCache: true, // warnings shown only on first compilation
+  })
 
   testCase.runWithTemplates(allValidPackageSets, 0, (runTest, { testLabel }) => {
     it(testLabel, () => {
diff --git a/e2e/__tests__/logger.test.ts b/e2e/__tests__/logger.test.ts
index a983471104..0352fa9eaf 100644
--- a/e2e/__tests__/logger.test.ts
+++ b/e2e/__tests__/logger.test.ts
@@ -19,15 +19,16 @@ describe('With unsupported version test', () => {
 describe('TS_JEST_LOG', () => {
   const testCase = configureTestCase('simple', {
     env: { TS_JEST_LOG: 'ts-jest.log' },
+    noCache: true,
   })
 
   testCase.runWithTemplates(allValidPackageSets, 0, (runTest, { templateName }) => {
-    it(`should pass and create log file when using tempalte "${templateName}"`, () => {
+    it(`should pass and create log file when using template "${templateName}"`, () => {
       const result = runTest()
       expect(result.status).toBe(0)
       expect(existsSync(result.logFilePath))
       const filteredEntries = result.logFileEntries
-        // keep only debu and above
+        // keep only debug and above
         .filter(m => (m.context[LogContexts.logLevel] || 0) >= LogLevels.debug)
         // simplify entires
         .map(e => result.normalize(`[level:${e.context[LogContexts.logLevel]}] ${e.message}`))
diff --git a/e2e/__tests__/simple.test.ts b/e2e/__tests__/ts-jest-checks.test.ts
similarity index 72%
rename from e2e/__tests__/simple.test.ts
rename to e2e/__tests__/ts-jest-checks.test.ts
index c416c4cdb7..99a0554378 100644
--- a/e2e/__tests__/simple.test.ts
+++ b/e2e/__tests__/ts-jest-checks.test.ts
@@ -1,14 +1,13 @@
 import { allValidPackageSets } from '../__helpers__/templates'
 import { configureTestCase } from '../__helpers__/test-case'
 
-describe('Simple test', () => {
-  const testCase = configureTestCase('simple')
+describe('ts-jest internal checks test', () => {
+  const testCase = configureTestCase('ts-jest-checks')
 
   testCase.runWithTemplates(allValidPackageSets, 0, (runTest, { testLabel }) => {
     it(testLabel, () => {
       const result = runTest()
       expect(result.status).toBe(0)
-      expect(result).toMatchSnapshot()
     })
   })
 })
diff --git a/e2e/jest.config.js b/e2e/jest.config.js
index dfdb22a59c..2ce70c5dc7 100644
--- a/e2e/jest.config.js
+++ b/e2e/jest.config.js
@@ -11,4 +11,5 @@ module.exports = {
     '<rootDir>/e2e/__serializers__/processed-source.ts',
   ],
   verbose: true,
+  cacheDirectory: '<rootDir>/.cache/e2e',
 }
diff --git a/jest.config.js b/jest.config.js
index b11cb8a378..a056994a39 100644
--- a/jest.config.js
+++ b/jest.config.js
@@ -15,4 +15,5 @@ module.exports = {
   moduleFileExtensions: ['ts', 'tsx', 'js', 'jsx', 'json'],
   testEnvironment: 'node',
   snapshotSerializers: ['<rootDir>/src/__serializers__/processed-source.ts'],
+  cacheDirectory: '<rootDir>/.cache/unit',
 }
diff --git a/package.json b/package.json
index f6db519180..73b72b6848 100644
--- a/package.json
+++ b/package.json
@@ -4,35 +4,36 @@
   "main": "dist/index.js",
   "types": "dist/index.d.ts",
   "bin": "cli.js",
-  "description": "A preprocessor with sourcemap support to help use Typescript with Jest",
+  "description": "A preprocessor with source maps support to help use TypeScript with Jest",
   "scripts": {
     "prebuild": "node scripts/clean-dist.js",
     "build": "tsc -p tsconfig.build.json",
+    "postbuild": "node scripts/post-build.js",
     "build:watch": "tsc -p tsconfig.build.json -w",
     "clean": "node scripts/clean.js",
-    "pretest": "run-s typecheck lint",
+    "pretest": "npm run lint",
     "test": "run-s -s test:e2e \"test:unit -- {@}\" --",
     "test:prepare": "npm run test:e2e -- --prepareOnly",
     "test:e2e": "node scripts/e2e.js",
-    "test:unit": "jest",
+    "test:unit": "node_modules/.bin/jest",
     "test:external": "node scripts/test-external-project.js",
     "lint": "run-s lint:ts lint:js",
-    "lint:js": "eslint . -f stylish",
-    "lint:ts": "tslint -t stylish --project .",
+    "lint:js": "node_modules/.bin/eslint . -f stylish",
+    "lint:ts": "node_modules/.bin/tslint -t stylish --project .",
     "lint:fix": "run-s lint:fix:ts lint:fix:js",
-    "lint:fix:js": "eslint . --fix",
-    "lint:fix:ts": "tslint --fix --project .",
-    "typecheck": "tsc -p . --noEmit",
+    "lint:fix:js": "node_modules/.bin/eslint . --fix",
+    "lint:fix:ts": "node_modules/.bin/tslint --fix --project .",
+    "typecheck": "node_modules/.bin/tsc -p .",
     "doc": "cd docs && bundle exec jekyll serve --livereload",
     "doc:link": "git worktree add docs/_site gh-pages",
     "doc:unlink": "git worktree prune",
     "doc:build": "cd docs && bundle exec jekyll build",
     "doc:build-commit": "npm run doc:build && cd docs/_site && git add --all && git commit -m \"Updates github pages\"",
+    "changelog": "node_modules/.bin/conventional-changelog -p angular -i CHANGELOG.md -s -r 0",
     "prepare": "npm run build",
     "prepublishOnly": "npm run test",
-    "changelog": "conventional-changelog -p angular -i CHANGELOG.md -s -r 0",
-    "commitmsg": "commitlint -E GIT_PARAMS",
-    "precommit": "lint-staged",
+    "commitmsg": "node_modules/.bin/commitlint -E GIT_PARAMS",
+    "precommit": "node_modules/.bin/lint-staged",
     "postcommit": "git reset",
     "preversion": "npm run test",
     "version": "npm run changelog && git add CHANGELOG.md"
diff --git a/scripts/e2e.js b/scripts/e2e.js
index 3d988bf653..dcc9fcb2ac 100755
--- a/scripts/e2e.js
+++ b/scripts/e2e.js
@@ -8,7 +8,7 @@ const path = require('path')
 const Paths = require('./lib/paths')
 const { createHash } = require('crypto')
 const logger = require('./lib/logger')
-const { createBundle, packageDigest } = require('./lib/bundle')
+const { createBundle, readPackageDigest } = require('./lib/bundle')
 const npm = require('./lib/npm')
 
 const configFile = path.join(Paths.e2eRootDir, 'jest.config.js')
@@ -49,8 +49,7 @@ function setupE2e() {
   )
 
   // get the hash of the bundle (to know if we should install it again or not)
-  // we need to compute it ourselfs as the npm pack creates different tgz even tho content has not changed
-  const bundleHash = packageDigest(bundle)
+  const bundleHash = readPackageDigest()
   log('ts-jest digest:', bundleHash)
 
   // ensure directory exists before copying over
@@ -166,8 +165,8 @@ setupE2e()
 log('templates are ready')
 
 if (!prepareOnly) {
-  log('clearing Jest cache')
-  spawnSync('jest', ['--clearCache'])
+  // log('clearing Jest cache')
+  // spawnSync('jest', ['--clearCache'])
 
   log('running tests')
   jest.run(['--config', configFile, ...parentArgs])
diff --git a/scripts/lib/bundle.js b/scripts/lib/bundle.js
index a70b2e08b7..2c32874c38 100644
--- a/scripts/lib/bundle.js
+++ b/scripts/lib/bundle.js
@@ -1,8 +1,8 @@
 const npm = require('./npm')
 const logger = require('./logger')
-const { rootDir } = require('./paths')
+const { rootDir, pkgDigestFile } = require('./paths')
 const { join, resolve } = require('path')
-const { readFileSync, statSync } = require('fs')
+const { readFileSync, statSync, writeFileSync, existsSync } = require('fs-extra')
 const { createHash } = require('crypto')
 const { sync: globIgnore } = require('glob-gitignore')
 
@@ -19,7 +19,11 @@ function createBundle(log = logger.log.bind(logger)) {
   return join(rootDir, res.stdout.toString().trim())
 }
 
-function packageDigest() {
+function readPackageDigest() {
+  return existsSync(pkgDigestFile) ? readFileSync(pkgDigestFile, 'utf8') : undefined
+}
+
+function computePackageDigest(noWriteFile = false) {
   const files = globIgnore(join(rootDir, '**'), {
     ignore: readFileSync(join(rootDir, '.npmignore'))
       .toString('utf8')
@@ -28,14 +32,19 @@ function packageDigest() {
   })
   const hash = createHash('sha1')
   files.sort().forEach(file => {
-    if (statSync(file).isDirectory()) return
+    if (file === pkgDigestFile || statSync(file).isDirectory()) return
     hash.update(readFileSync(resolve(file)))
     hash.update('\x00')
   })
-  return hash.digest('hex')
+  const digest = hash.digest('hex')
+  if (!noWriteFile) {
+    writeFileSync(pkgDigestFile, digest, 'utf8')
+  }
+  return digest
 }
 
 module.exports = {
   createBundle,
-  packageDigest,
+  computePackageDigest,
+  readPackageDigest,
 }
diff --git a/scripts/lib/paths.d.ts b/scripts/lib/paths.d.ts
index 6a346dcd24..15e6af7057 100644
--- a/scripts/lib/paths.d.ts
+++ b/scripts/lib/paths.d.ts
@@ -1,4 +1,6 @@
 declare const rootDir: string
+declare const cacheDir: string
+declare const pkgDigestFile: string
 declare const e2eSourceDir: string
 declare const e2eRootDir: string
 declare const e2eWorkDir: string
@@ -11,6 +13,8 @@ declare const e2eTestsDir: string
 
 export {
   rootDir,
+  cacheDir,
+  pkgDigestFile,
   e2eSourceDir,
   e2eRootDir,
   e2eWorkDir,
diff --git a/scripts/lib/paths.js b/scripts/lib/paths.js
index 8abc889a5a..1b7db61525 100644
--- a/scripts/lib/paths.js
+++ b/scripts/lib/paths.js
@@ -2,6 +2,8 @@ const path = require('path')
 const os = require('os')
 
 const rootDir = path.resolve(__dirname, '..', '..')
+const cacheDir = path.join(rootDir, '.cache')
+const pkgDigestFile = path.join(rootDir, '.ts-jest-digest')
 const distDir = path.join(rootDir, 'dist')
 const testsRootDir = path.join(rootDir, 'tests')
 const e2eRootDir = path.join(rootDir, 'e2e')
@@ -15,6 +17,8 @@ const e2eWorkTemplatesDir = path.join(e2eWorkDir, '__templates__')
 const e2eWotkDirLink = path.join(e2eRootDir, '__workdir_synlink__')
 
 module.exports = {
+  pkgDigestFile,
+  cacheDir,
   rootDir,
   e2eSourceDir,
   e2eRootDir,
diff --git a/scripts/post-build.js b/scripts/post-build.js
new file mode 100644
index 0000000000..c88e7b5796
--- /dev/null
+++ b/scripts/post-build.js
@@ -0,0 +1,3 @@
+const { computePackageDigest } = require('./lib/bundle')
+
+computePackageDigest()
diff --git a/src/__mocks__/index.ts b/src/__mocks__/index.ts
new file mode 100644
index 0000000000..54c4bda3d1
--- /dev/null
+++ b/src/__mocks__/index.ts
@@ -0,0 +1,6 @@
+export const version = '1.2.3-test.0'
+export const digest = 'a0d51ca854194df8191d0e65c0ca4730f510f332'
+export const createTransformer = jest.fn()
+export const jestPreset = { jestPreset: true }
+export const createJestPreset = jest.fn()
+export const pathsToModuleNameMapper = jest.fn()
diff --git a/src/compiler.spec.ts b/src/compiler.spec.ts
index 6603bcb703..ad984def7a 100644
--- a/src/compiler.spec.ts
+++ b/src/compiler.spec.ts
@@ -1,5 +1,6 @@
 // tslint:disable:max-line-length
 import { LogLevels } from 'bs-logger'
+import { removeSync, writeFileSync } from 'fs-extra'
 
 import * as fakers from './__helpers__/fakers'
 import { logTargetMock } from './__helpers__/mocks'
@@ -34,8 +35,8 @@ beforeEach(() => {
   logTarget.clear()
 })
 
-describe('isolatedModules', () => {
-  const compiler = makeCompiler()
+describe('typings', () => {
+  const compiler = makeCompiler({ tsJestConfig: { tsConfig: false } })
   it('should report diagnostics related to typings', () => {
     expect(() =>
       compiler.compile(
@@ -55,7 +56,7 @@ foo.ts(4,7): error TS2322: Type 'string' is not assignable to type 'boolean'."
 })
 
 describe('source-maps', () => {
-  const compiler = makeCompiler()
+  const compiler = makeCompiler({ tsJestConfig: { tsConfig: false } })
   it('should have correct source maps', () => {
     const source = 'const f = (v: number) => v\nconst t: number = f(5)'
     const compiled = compiler.compile(source, __filename)
@@ -74,6 +75,7 @@ describe('cache', () => {
   const tmp = tempDir('compiler')
   const compiler = makeCompiler({
     jestConfig: { cache: true, cacheDirectory: tmp },
+    tsJestConfig: { tsConfig: false },
   })
   const source = 'console.log("hello")'
 
@@ -107,12 +109,11 @@ Array [
 
     expect(new ProcessedSource(compiled1, __filename)).toMatchInlineSnapshot(`
   ===[ FILE: src/compiler.spec.ts ]===============================================
-  "use strict";
   console.log("hello");
-  //# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJmaWxlIjoiPGN3ZD4vc3JjL2NvbXBpbGVyLnNwZWMudHMiLCJtYXBwaW5ncyI6IjtBQUFBLE9BQU8sQ0FBQyxHQUFHLENBQUMsT0FBTyxDQUFDLENBQUEiLCJuYW1lcyI6W10sInNvdXJjZXMiOlsiPGN3ZD4vc3JjL2NvbXBpbGVyLnNwZWMudHMiXSwic291cmNlc0NvbnRlbnQiOlsiY29uc29sZS5sb2coXCJoZWxsb1wiKSJdLCJ2ZXJzaW9uIjozfQ==
+  //# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJmaWxlIjoiPGN3ZD4vc3JjL2NvbXBpbGVyLnNwZWMudHMiLCJtYXBwaW5ncyI6IkFBQUEsT0FBTyxDQUFDLEdBQUcsQ0FBQyxPQUFPLENBQUMsQ0FBQSIsIm5hbWVzIjpbXSwic291cmNlcyI6WyI8Y3dkPi9zcmMvY29tcGlsZXIuc3BlYy50cyJdLCJzb3VyY2VzQ29udGVudCI6WyJjb25zb2xlLmxvZyhcImhlbGxvXCIpIl0sInZlcnNpb24iOjN9
   ===[ INLINE SOURCE MAPS ]=======================================================
   file: <cwd>/src/compiler.spec.ts
-  mappings: ';AAAA,OAAO,CAAC,GAAG,CAAC,OAAO,CAAC,CAAA'
+  mappings: 'AAAA,OAAO,CAAC,GAAG,CAAC,OAAO,CAAC,CAAA'
   names: []
   sources:
     - <cwd>/src/compiler.spec.ts
@@ -154,8 +155,39 @@ describe('isolatedModules', () => {
   })
 })
 
+describe('allowJs', () => {
+  const compiler = makeCompiler({ tsJestConfig: { tsConfig: { allowJs: true } } })
+  const fileName = `${__filename}.test.js`
+  afterAll(() => {
+    removeSync(fileName)
+  })
+  it('should compile js file', () => {
+    const source = 'export default 42'
+    writeFileSync(fileName, source, 'utf8')
+    const compiled = compiler.compile(source, fileName)
+    const processed = new ProcessedSource(compiled, fileName)
+    expect(processed).toMatchInlineSnapshot(`
+  ===[ FILE: src/compiler.spec.ts.test.js ]=======================================
+  "use strict";
+  Object.defineProperty(exports, "__esModule", { value: true });
+  exports.default = 42;
+  //# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJmaWxlIjoiPGN3ZD4vc3JjL2NvbXBpbGVyLnNwZWMudHMudGVzdC5qcyIsIm1hcHBpbmdzIjoiOztBQUFBLGtCQUFlLEVBQUUsQ0FBQSIsIm5hbWVzIjpbXSwic291cmNlcyI6WyI8Y3dkPi9zcmMvY29tcGlsZXIuc3BlYy50cy50ZXN0LmpzIl0sInNvdXJjZXNDb250ZW50IjpbImV4cG9ydCBkZWZhdWx0IDQyIl0sInZlcnNpb24iOjN9
+  ===[ INLINE SOURCE MAPS ]=======================================================
+  file: <cwd>/src/compiler.spec.ts.test.js
+  mappings: ';;AAAA,kBAAe,EAAE,CAAA'
+  names: []
+  sources:
+    - <cwd>/src/compiler.spec.ts.test.js
+  sourcesContent:
+    - export default 42
+  version: 3
+  ================================================================================
+`)
+  })
+})
+
 describe('getTypeInfo', () => {
-  const compiler = makeCompiler()
+  const compiler = makeCompiler({ tsJestConfig: { tsConfig: false } })
   const source = `
 type MyType {
   /** the prop 1! */
diff --git a/src/compiler.ts b/src/compiler.ts
index 770aa583bd..d910f99b57 100644
--- a/src/compiler.ts
+++ b/src/compiler.ts
@@ -191,11 +191,13 @@ export function createCompiler(configs: ConfigSet): TsCompiler {
         configs.raiseDiagnostics(diagnostics, fileName, logger)
       }
 
+      /* istanbul ignore next (this should never happen but is kept for security) */
       if (output.emitSkipped) {
         throw new TypeError(`${relative(cwd, fileName)}: Emit skipped`)
       }
 
       // Throw an error when requiring `.d.ts` files.
+      /* istanbul ignore next (this should never happen but is kept for security) */
       if (output.outputFiles.length === 0) {
         throw new TypeError(
           interpolate(Errors.UnableToRequireDefinitionFile, {
diff --git a/src/config/config-set.spec.ts b/src/config/config-set.spec.ts
index e5a7bc3988..a357fc9bbe 100644
--- a/src/config/config-set.spec.ts
+++ b/src/config/config-set.spec.ts
@@ -2,7 +2,7 @@ import { testing } from 'bs-logger'
 import { resolve } from 'path'
 import ts, { Diagnostic, ModuleKind, ScriptTarget } from 'typescript'
 
-import { version as currentVersion } from '../../package.json'
+import * as _myModule from '..'
 import * as fakers from '../__helpers__/fakers'
 import { logTargetMock, mocked } from '../__helpers__/mocks'
 import { TsJestGlobalOptions } from '../types'
@@ -12,8 +12,10 @@ import { normalizeSlashes } from '../util/normalize-slashes'
 import { ConfigSet, IGNORE_DIAGNOSTIC_CODES, MATCH_NOTHING } from './config-set'
 
 jest.mock('../util/backports')
+jest.mock('../index')
 
 const backports = mocked(_backports)
+const myModule = mocked(_myModule)
 
 backports.backportJestConfig.mockImplementation((_, config) => ({
   ...config,
@@ -385,7 +387,7 @@ describe('versions', () => {
     it('should return correct version map', () => {
       expect(createConfigSet().versions).toEqual({
         jest: pkgVersion('jest'),
-        'ts-jest': currentVersion,
+        'ts-jest': myModule.version,
         typescript: pkgVersion('typescript'),
       })
     })
@@ -397,13 +399,19 @@ describe('versions', () => {
         'babel-core': pkgVersion('babel-core'),
         'babel-jest': pkgVersion('babel-jest'),
         jest: pkgVersion('jest'),
-        'ts-jest': currentVersion,
+        'ts-jest': myModule.version,
         typescript: pkgVersion('typescript'),
       })
     })
   })
 }) // versions
 
+describe('tsJestDigest', () => {
+  it('should be the package digest', () => {
+    expect(createConfigSet().tsJestDigest).toBe(myModule.digest)
+  })
+}) // tsJestDigest
+
 describe('tsconfig', () => {
   it('should return input tsconfig', () => {
     const cs = createConfigSet({ tsJestConfig: { tsConfig: { target: 'ES6' } } as any })
@@ -468,8 +476,9 @@ describe('cacheKey', () => {
     const val = cs.jsonValue.value
     delete val.versions
     cs.jsonValue.value = val
+    // digest is mocked in src/__mocks__/index.ts
     expect(cs.cacheKey).toMatchInlineSnapshot(
-      `"{\\"jest\\":{\\"__backported\\":true,\\"globals\\":{}},\\"transformers\\":[\\"hoisting-jest-mock@1\\"],\\"tsJest\\":{\\"compiler\\":\\"typescript\\",\\"diagnostics\\":{\\"ignoreCodes\\":[6059,18002,18003],\\"pretty\\":true,\\"throws\\":true},\\"isolatedModules\\":false,\\"transformers\\":[]},\\"tsconfig\\":{\\"compilerOptions\\":{}}}"`,
+      `"{\\"digest\\":\\"a0d51ca854194df8191d0e65c0ca4730f510f332\\",\\"jest\\":{\\"__backported\\":true,\\"globals\\":{}},\\"transformers\\":[\\"hoisting-jest-mock@1\\"],\\"tsJest\\":{\\"compiler\\":\\"typescript\\",\\"diagnostics\\":{\\"ignoreCodes\\":[6059,18002,18003],\\"pretty\\":true,\\"throws\\":true},\\"isolatedModules\\":false,\\"transformers\\":[]},\\"tsconfig\\":{\\"declaration\\":false,\\"inlineSourceMap\\":false,\\"inlineSources\\":true,\\"module\\":1,\\"noEmit\\":false,\\"outDir\\":\\"$$ts-jest$$\\",\\"removeComments\\":false,\\"sourceMap\\":true,\\"target\\":1}}"`,
     )
   })
 }) // cacheKey
@@ -479,13 +488,15 @@ describe('jsonValue', () => {
     const cs = createConfigSet({ tsJestConfig: { tsConfig: false } as any })
     const val = cs.jsonValue.valueOf()
     expect(cs.toJSON()).toEqual(val)
-    // it will change each time we upgrade and we tested those in the `version` block
+    // it will change each time we upgrade – we tested those in the `version` block
     expect(val.versions).toEqual(cs.versions)
     delete val.versions
 
+    // digest is mocked in src/__mocks__/index.ts
     expect(val).toMatchInlineSnapshot(`
 Object {
   "babel": undefined,
+  "digest": "a0d51ca854194df8191d0e65c0ca4730f510f332",
   "jest": Object {
     "__backported": true,
     "globals": Object {},
@@ -511,7 +522,16 @@ Object {
     "tsConfig": undefined,
   },
   "tsconfig": Object {
-    "compilerOptions": Object {},
+    "configFilePath": undefined,
+    "declaration": false,
+    "inlineSourceMap": false,
+    "inlineSources": true,
+    "module": 1,
+    "noEmit": false,
+    "outDir": "$$ts-jest$$",
+    "removeComments": false,
+    "sourceMap": true,
+    "target": 1,
   },
 }
 `)
diff --git a/src/config/config-set.ts b/src/config/config-set.ts
index 00acbfafc9..4d1c1debfd 100644
--- a/src/config/config-set.ts
+++ b/src/config/config-set.ts
@@ -23,7 +23,7 @@ import {
   SourceFile,
 } from 'typescript'
 
-import { version as myVersion } from '..'
+import { digest as MY_DIGEST, version as MY_VERSION } from '..'
 import { createCompiler } from '../compiler'
 import { internals as internalAstTransformers } from '../transformers'
 import {
@@ -229,7 +229,7 @@ export class ConfigSet {
         map[name] = getPackageVersion(name) || '-'
         return map
       },
-      { 'ts-jest': myVersion } as Record<string, string>,
+      { 'ts-jest': MY_VERSION } as Record<string, string>,
     )
   }
 
@@ -438,10 +438,10 @@ export class ConfigSet {
         compiler: this.tsJest.compiler,
         compilerOptions: this.typescript.options,
         isolatedModules: this.tsJest.isolatedModules,
-        ignoreDiagnostics: this.tsJest.diagnostics.ignoreCodes,
+        diagnostics: this.tsJest.diagnostics,
       }),
     )
-    const res = join(this.jest.cacheDirectory, `ts-jest-${cacheSuffix}`)
+    const res = join(this.jest.cacheDirectory, 'ts-jest', cacheSuffix.substr(0, 2), cacheSuffix.substr(2))
     logger.debug({ cacheDirectory: res }, `will use file caching`)
     return res
   }
@@ -489,6 +489,11 @@ export class ConfigSet {
     return !!process.env.TS_JEST_DOCTOR
   }
 
+  @Memoize()
+  get tsJestDigest(): string {
+    return MY_DIGEST
+  }
+
   /**
    * @internal
    */
@@ -505,11 +510,12 @@ export class ConfigSet {
 
     return new JsonableValue({
       versions: this.versions,
+      digest: this.tsJestDigest,
       transformers: this.astTransformers.map(t => `${t.name}@${t.version}`),
       jest,
       tsJest: this.tsJest,
       babel: this.babel,
-      tsconfig: this.tsconfig,
+      tsconfig: this.typescript.options,
     })
   }
 
diff --git a/src/index.ts b/src/index.ts
index 76e8775a37..15806be569 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,3 +1,6 @@
+import { readFileSync } from 'fs'
+import { resolve } from 'path'
+
 import { createJestPreset } from './config/create-jest-preset'
 import { pathsToModuleNameMapper } from './config/paths-to-module-name-mapper'
 import { TsJestTransformer } from './ts-jest-transformer'
@@ -6,6 +9,7 @@ import { VersionCheckers } from './util/version-checkers'
 
 // tslint:disable-next-line:no-var-requires
 export const version: string = require('../package.json').version
+export const digest: string = readFileSync(resolve(__dirname, '..', '.ts-jest-digest'), 'utf8')
 
 let transformer!: TsJestTransformer
 function defaultTransformer(): TsJestTransformer {