tweak docs, fix a test

docs/Configuration.md

@@ -152,18 +152,18 @@ Note that, if you specify a global reference value (like an object or array) her
 
 ### `mapCoverage` [boolean]
 
-##### available in Jest **19.0.0+**
+##### available in Jest **20.0.0+**
 
 Default: `false`
 
-If you have [transformers](#transform-object-string-string) configured that emit source maps, Jest will use them to map code coverage against the original source code when writing [reports](#coveragereporters-array-string) and checking [thresholds](#coveragethreshold-object). This can be resource-intensive. If Jest is taking a long time to calculate coverage at the end of a test run, try setting this option to `false`.
+If you have [transformers](#transform-object-string-string) configured that emit source maps, Jest will use them to try and map code coverage against the original source code when writing [reports](#coveragereporters-array-string) and checking [thresholds](#coveragethreshold-object). This is done on a best-effort basis as some compile-to-JavaScript languages may provide more accurate source maps than others. This can also be resource-intensive. If Jest is taking a long time to calculate coverage at the end of a test run, try setting this option to `false`.
 
-Both inline source maps and source maps returned directly from a transformer are supported. Source map URLs are not supported because Jest may not be able to locate them. To return source maps from a transformer, the `process` function can return an object like the following. The sourceMap property may either be an object, or a string of JSON.
+Both inline source maps and source maps returned directly from a transformer are supported. Source map URLs are not supported because Jest may not be able to locate them. To return source maps from a transformer, the `process` function can return an object like the following. The `map` property may either be the source map object, or the source map object as a JSON string.
 
 ```js
 return {
-  content: 'the code',
-  sourceMap: 'the source map',
+  code: 'the code',
+  map: 'the source map',
 };
 ```
 

packages/jest-runtime/src/__tests__/transform-test.js

@@ -226,7 +226,7 @@ describe('transform', () => {
     expect(vm.Script.mock.calls[2][0]).toMatchSnapshot();
   });
 
-  it('instruments with source map if preprocessor supplies it', () => {
+  it('writes source map if preprocessor supplies it', () => {
     config = Object.assign(config, {
       collectCoverage: true,
       mapCoverage: true,
@@ -252,7 +252,7 @@ describe('transform', () => {
     );
   });
 
-  it('instruments with source map if preprocessor inlines it', () => {
+  it('writes source map if preprocessor inlines it', () => {
     config = Object.assign(config, {
       collectCoverage: true,
       mapCoverage: true,
@@ -279,21 +279,21 @@ describe('transform', () => {
     );
   });
 
-  it('does not instrument with source map if mapCoverage config option is false', () => {
+  it('does not write source map if mapCoverage config option is false', () => {
     config = Object.assign(config, {
       collectCoverage: true,
       mapCoverage: false,
       transform: [['^.+\\.js$', 'preprocessor-with-sourcemaps']],
     });
 
-    const sourceMap = { 
+    const map = { 
       mappings: ';AAAA', 
       version: 3, 
     };
 
     require('preprocessor-with-sourcemaps').process.mockReturnValue({
-      content: 'content',
-      sourceMap,
+      code: 'content',
+      map,
     });
 
     const result = transform('/fruits/banana.js', config);

types/TestResult.js

@@ -21,7 +21,6 @@ export type RawFileCoverage = {|
   statementMap: { [statementId: number]: any },
   branchMap: { [branchId: number]: any },
   inputSourceMap?: Object,
-  inputSourceMapPath?: string,
 |};
 
 export type RawCoverage = {