fix: ensure all packages correctly downlevel TS files

CHANGELOG.md

@@ -4,6 +4,8 @@
 
 ### Fixes
 
+- `[*]` Verify all packages are properly downleveled for older versions of TypeScript
+
 ### Chore & Maintenance
 
 ### Performance
@@ -12,7 +14,7 @@
 
 ### Fixes
 
-- `[jest-environment-node]` Remove `getVmContext` from Node env on older versions of Node ([#9706](https://github.com/facebook/jest/pull/9706))
+- `[jest-environment-node]` Remove `getVmContext` from Node env on older versions of Node ([#9708](https://github.com/facebook/jest/pull/9708))
 - `[jest-runtime]` Return constructable class from `require('module')` ([#9711](https://github.com/facebook/jest/pull/9711))
 
 ## 25.2.1

packages/jest-console/src/CustomConsole.ts

@@ -51,7 +51,8 @@ export default class CustomConsole extends Console {
     );
   }
 
-  assert(value: unknown, message?: string | Error): asserts value {
+  // use `asserts` when https://github.com/sandersn/downlevel-dts/issues/32 is fixed
+  assert(value: unknown, message?: string | Error): void {
     try {
       assert(value, message);
     } catch (error) {

packages/jest-core/package.json

@@ -4,6 +4,13 @@
   "version": "25.2.2",
   "main": "build/jest.js",
   "types": "build/jest.d.ts",
+  "typesVersions": {
+    "<3.8": {
+      "build/*": [
+        "build/ts3.4/*"
+      ]
+    }
+  },
   "dependencies": {
     "@jest/console": "^25.2.1",
     "@jest/reporters": "^25.2.1",

packages/jest-docblock/package.json

@@ -8,6 +8,14 @@
   },
   "license": "MIT",
   "main": "build/index.js",
+  "types": "build/index.d.ts",
+  "typesVersions": {
+    "<3.8": {
+      "build/*": [
+        "build/ts3.4/*"
+      ]
+    }
+  },
   "dependencies": {
     "detect-newline": "^3.0.0"
   },

packages/jest-phabricator/package.json

@@ -7,6 +7,13 @@
     "directory": "packages/jest-phabricator"
   },
   "types": "build/index.d.ts",
+  "typesVersions": {
+    "<3.8": {
+      "build/*": [
+        "build/ts3.4/*"
+      ]
+    }
+  },
   "dependencies": {
     "@jest/test-result": "^25.2.1"
   },

packages/jest-transform/package.json

@@ -8,6 +8,14 @@
   },
   "license": "MIT",
   "main": "build/index.js",
+  "types": "build/index.d.ts",
+  "typesVersions": {
+    "<3.8": {
+      "build/*": [
+        "build/ts3.4/*"
+      ]
+    }
+  },
   "dependencies": {
     "@babel/core": "^7.1.0",
     "@jest/types": "^25.2.1",

packages/jest-transform/src/types.ts

@@ -24,8 +24,11 @@ export type Options = ShouldInstrumentOptions &
     isInternalModule: boolean;
   }>;
 
+// extends directly after https://github.com/sandersn/downlevel-dts/issues/33 is fixed
+type SourceMapWithVersion = Omit<RawSourceMap, 'version'>;
+
 // This is fixed in source-map@0.7.x, but we can't upgrade yet since it's async
-interface FixedRawSourceMap extends Omit<RawSourceMap, 'version'> {
+interface FixedRawSourceMap extends SourceMapWithVersion {
   version: number;
 }
 

packages/jest-types/src/Global.ts

@@ -83,8 +83,10 @@ export interface GlobalAdditions {
   spyOn: () => void;
   spyOnProperty: () => void;
 }
-export interface Global
-  extends GlobalAdditions,
-    Omit<NodeJS.Global, keyof GlobalAdditions> {
+
+// extends directly after https://github.com/sandersn/downlevel-dts/issues/33 is fixed
+type NodeGlobalWithoutAdditions = Omit<NodeJS.Global, keyof GlobalAdditions>;
+
+export interface Global extends GlobalAdditions, NodeGlobalWithoutAdditions {
   [extras: string]: any;
 }

packages/jest-watcher/package.json

@@ -3,6 +3,14 @@
   "description": "Delightful JavaScript Testing.",
   "version": "25.2.1",
   "main": "build/index.js",
+  "types": "build/index.d.ts",
+  "typesVersions": {
+    "<3.8": {
+      "build/*": [
+        "build/ts3.4/*"
+      ]
+    }
+  },
   "dependencies": {
     "@jest/test-result": "^25.2.1",
     "@jest/types": "^25.2.1",

packages/jest/package.json

@@ -4,6 +4,13 @@
   "version": "25.2.2",
   "main": "build/jest.js",
   "types": "build/jest.d.ts",
+  "typesVersions": {
+    "<3.8": {
+      "build/*": [
+        "build/ts3.4/*"
+      ]
+    }
+  },
   "dependencies": {
     "@jest/core": "^25.2.2",
     "import-local": "^3.0.2",

scripts/buildTs.js

@@ -44,12 +44,31 @@ try {
   );
   console.error(e.stack);
   process.exitCode = 1;
+  return;
 }
 
 const downlevelArgs = ['--silent', 'downlevel-dts', 'build', 'build/ts3.4'];
 
 console.log(chalk.inverse(' Downleveling TypeScript definition files '));
 
+packagesWithTs.forEach(pkgDir => {
+  const pkg = require(pkgDir + '/package.json');
+
+  if (!pkg.types) {
+    throw new Error(`Package ${pkg.name} is missing \`types\` field`);
+  }
+
+  if (!pkg.typesVersions) {
+    throw new Error(`Package ${pkg.name} is missing \`typesVersions\` field`);
+  }
+
+  if (pkg.main.replace(/\.js$/, '.d.ts') !== pkg.types) {
+    throw new Error(
+      `\`main\` and \`types\` field of ${pkg.name} does not match`
+    );
+  }
+});
+
 // we want to limit the number of processes we spawn
 const cpus = Math.max(1, os.cpus().length - 1);