feat(tests): add setup/teardown functions (#14)

.babelrc

@@ -2,7 +2,7 @@
   "presets": [
     ["env", {
       "targets": {
-        "node": 4.5
+        "node": "4.5"
       }
     }],
     "stage-2"

README.md

@@ -234,6 +234,20 @@ of the following:
 }
 ```
 
+#### setup
+
+If you need something set up before a particular test is run, you can do this
+with `setup`. This function will be run before the test runs. It can return
+a function which will be treated as a `teardown` function. It can also return
+a promise. If that promise resolves to a function, that will be treated as a
+`teardown` function.
+
+#### teardown
+
+If you set up some state, it's quite possible you want to tear it down. You can
+either define this as its own property, or you can return it from the `setup`
+function. This can likewise return a promise if it's asynchronous.
+
 ## Examples
 
 ### Full Example + Docs
@@ -242,6 +256,9 @@ of the following:
 import pluginTester from 'babel-plugin-tester'
 import identifierReversePlugin from '../identifier-reverse-plugin'
 
+// NOTE: you can use beforeAll, afterAll, beforeEach, and afterEach
+// right here if you need
+
 pluginTester({
   // required
   plugin: identifierReversePlugin,
@@ -334,6 +351,20 @@ pluginTester({
         optionA: false,
       },
     },
+    {
+      title: 'unchanged code',
+      setup() {
+        // runs before this test
+        return function teardown() {
+          // runs after this tests
+        }
+        // can also return a promise
+      },
+      teardown() {
+        // runs after this test
+        // can return a promise
+      },
+    },
   ],
 })
 ```

package.json

@@ -16,7 +16,7 @@
   "author": "Kent C. Dodds <kent@doddsfamily.us> (http://kentcdodds.com/)",
   "license": "MIT",
   "dependencies": {
-    "babel-core": "^6.24.1",
+    "babel-core": "^6.25.0",
     "common-tags": "^1.4.0",
     "invariant": "^2.2.2",
     "lodash.merge": "^4.6.0",
@@ -26,24 +26,24 @@
   "devDependencies": {
     "all-contributors-cli": "^4.0.1",
     "babel-cli": "^6.23.0",
-    "babel-jest": "^20.0.1",
-    "babel-preset-env": "^1.2.0",
+    "babel-jest": "^20.0.3",
+    "babel-preset-env": "^1.5.2",
     "babel-preset-stage-2": "^6.22.0",
     "babel-register": "^6.23.0",
     "codecov": "^2.1.0",
     "commitizen": "^2.9.6",
     "cz-conventional-changelog": "^2.0.0",
     "eslint": "^3.17.0",
-    "eslint-config-kentcdodds": "^12.0.0",
-    "husky": "^0.13.2",
-    "jest-cli": "^20.0.1",
-    "lint-staged": "^3.3.1",
-    "nps": "^5.0.3",
+    "eslint-config-kentcdodds": "^12.4.1",
+    "husky": "^0.14.1",
+    "jest-cli": "^20.0.4",
+    "lint-staged": "^4.0.0",
+    "nps": "^5.3.2",
     "nps-utils": "^1.1.2",
     "opt-cli": "^1.5.1",
-    "prettier-eslint-cli": "^3.1.2",
+    "prettier-eslint-cli": "^4.1.1",
     "semantic-release": "^6.3.6",
-    "validate-commit-msg": "^2.11.1"
+    "validate-commit-msg": "^2.12.2"
   },
   "eslintConfig": {
     "extends": [
@@ -53,7 +53,10 @@
     ],
     "rules": {
       "func-style": "off",
-      "max-lines": ["error", 1000]
+      "max-lines": [
+        "error",
+        1000
+      ]
     }
   },
   "lint-staged": {

src/__tests__/__snapshots__/index.js.snap

@@ -32,7 +32,7 @@ exports[`throws error when function doesn't return true 1`] = `"test message"`;
 
 exports[`throws if output is incorrect 1`] = `"Output is incorrect."`;
 
-exports[`throws invariant if code is unchanged and snapshot is enabled 1`] = `"Code was unmodified but attempted to take a snapshot. If the code should not be modified, set \`snapshot: false\`"`;
+exports[`throws invariant if code is unchanged + snapshot enabled 1`] = `"Code was unmodified but attempted to take a snapshot. If the code should not be modified, set \`snapshot: false\`"`;
 
 exports[`throws invariant if snapshot and output are both provided 1`] = `"\`output\` cannot be provided with \`snapshot: true\`"`;