Add combined coverage threshold for directories

CHANGELOG.md

@@ -45,6 +45,8 @@
 
 ### Features
 
+* `[jest-cli]` Add combined coverage threshold for directories.
+  ([#4885](https://github.com/facebook/jest/pull/4885))
 * `[jest-mock]` Add `timestamps` to mock state.
   ([#4866](https://github.com/facebook/jest/pull/4866))
 * `[eslint-plugin-jest]` Add `prefer-to-have-length` lint rule.

docs/Configuration.md

@@ -165,20 +165,37 @@ _Note: Setting this option overwrites the default values. Add `"text"` or
 Default: `undefined`
 
 This will be used to configure minimum threshold enforcement for coverage
-results. If the thresholds are not met, jest will return failure. Thresholds,
-when specified as a positive number are taken to be the minimum percentage
-required. When a threshold is specified as a negative number it represents the
-maximum number of uncovered entities allowed. Thresholds can be specified as
-`global`, as `glob` paths or just paths. If globs or paths are specified
-alongside `global`, coverage data for matching paths will be subtracted from
-overall coverage and thresholds will be applied independently. Threshold for
-globs is applied to all files matching the glob. If the file specified by path
-is not found, error is returned.
-
-For example, statements: 90 implies minimum statement coverage is 90%.
-statements: -10 implies that no more than 10 uncovered statements are allowed.
-`global` branch threshold 50 will be applied to all files minus matching
-`./src/components/**/*.js` and `./src/api/very-important-module.js`.
+results. Thresholds can be specified as `global`, as
+a [glob](https://github.com/isaacs/node-glob#glob-primer), and as a directory or
+file path. If thresholds aren't met, jest will fail. Thresholds specified as a
+positive number are taken to be the minimum percentage required. Thresholds
+specified as a negative number represent the maximum number of uncovered
+entities allowed.
+
+For example, with the following configuration jest will fail if there is less than 80% branch, line, and function coverage, or if there are more than 10 uncovered statements:
+
+```json
+{
+  ...
+  "jest": {
+    "coverageThreshold": {
+      "global": {
+        "branches": 80,
+        "functions": 80,
+        "lines": 80,
+        "statements": -10
+      }
+    }
+  }
+}
+```
+
+If globs or paths are specified alongside `global`, coverage data for matching
+paths will be subtracted from overall coverage and thresholds will be applied
+independently. Thresholds for globs are applied to all files matching the
+glob. If the file specified by path is not found, error is returned.
+
+For example, with the following configuration:
 
 ```json
 {
@@ -191,10 +208,13 @@ statements: -10 implies that no more than 10 uncovered statements are allowed.
         "lines": 50,
         "statements": 50
       },
-      "./src/components/**/*.js": {
+      "./src/components/": {
         "branches": 40,
         "statements": 40
       },
+      "./src/reducers/**/*.js": {
+        "statements": 90,
+      },
       "./src/api/very-important-module.js": {
         "branches": 100,
         "functions": 100,
@@ -206,6 +226,15 @@ statements: -10 implies that no more than 10 uncovered statements are allowed.
 }
 ```
 
+Jest will fail if:
+
+ - The `./src/components` directory has less than 40% branch or statement coverage.
+ - One of the files matching the `./src/reducers/**/*.js` glob has less than 90%
+   statement coverage.
+ - The `./src/api/very-important-module.js` file has less than 100% coverage.
+ - Every remaining file combined has less than 50% coverage (`global`).
+
+
 ### `globals` [object]
 
 Default: `{}`

packages/jest-cli/src/reporters/__tests__/coverage_reporter.test.js

@@ -112,7 +112,7 @@ describe('onRunComplete', () => {
     });
   });
 
-  it('getLastError() returns an error when threshold is not met for global', () => {
+  test('getLastError() returns an error when threshold is not met for global', () => {
     const testReporter = new CoverageReporter(
       {
         collectCoverage: true,
@@ -134,7 +134,7 @@ describe('onRunComplete', () => {
       });
   });
 
-  it('getLastError() returns an error when threshold is not met for file', () => {
+  test('getLastError() returns an error when threshold is not met for file', () => {
     const covThreshold = {};
     [
       'global',
@@ -164,7 +164,7 @@ describe('onRunComplete', () => {
       });
   });
 
-  it('getLastError() returns `undefined` when threshold is met', () => {
+  test('getLastError() returns `undefined` when threshold is met', () => {
     const covThreshold = {};
     [
       'global',
@@ -194,7 +194,7 @@ describe('onRunComplete', () => {
       });
   });
 
-  it('getLastError() returns an error when threshold is for non-covered file', () => {
+  test('getLastError() returns an error when threshold is not met for non-covered file', () => {
     const testReporter = new CoverageReporter(
       {
         collectCoverage: true,
@@ -215,4 +215,70 @@ describe('onRunComplete', () => {
         expect(testReporter.getLastError().message.split('\n')).toHaveLength(1);
       });
   });
+
+  test('getLastError() returns an error when threshold is not met for directory', () => {
+    const testReporter = new CoverageReporter(
+      {
+        collectCoverage: true,
+        coverageThreshold: {
+          './path-test-files/glob-path/': {
+            statements: 100,
+          },
+        },
+      },
+      {
+        maxWorkers: 2,
+      },
+    );
+    testReporter.log = jest.fn();
+    return testReporter
+      .onRunComplete(new Set(), {}, mockAggResults)
+      .then(() => {
+        expect(testReporter.getLastError().message.split('\n')).toHaveLength(1);
+      });
+  });
+
+  test('getLastError() returns `undefined` when threshold is met for directory', () => {
+    const testReporter = new CoverageReporter(
+      {
+        collectCoverage: true,
+        coverageThreshold: {
+          './path-test-files/glob-path/': {
+            statements: 40,
+          },
+        },
+      },
+      {
+        maxWorkers: 2,
+      },
+    );
+    testReporter.log = jest.fn();
+    return testReporter
+      .onRunComplete(new Set(), {}, mockAggResults)
+      .then(() => {
+        expect(testReporter.getLastError()).toBeUndefined();
+      });
+  });
+
+  test('getLastError() returns an error when there is no coverage data for a threshold', () => {
+    const testReporter = new CoverageReporter(
+      {
+        collectCoverage: true,
+        coverageThreshold: {
+          './path/doesnt/exist': {
+            statements: 40,
+          },
+        },
+      },
+      {
+        maxWorkers: 2,
+      },
+    );
+    testReporter.log = jest.fn();
+    return testReporter
+      .onRunComplete(new Set(), {}, mockAggResults)
+      .then(() => {
+        expect(testReporter.getLastError().message.split('\n')).toHaveLength(1);
+      });
+  });
 });