Handle 'use strict'

.gitignore

@@ -43,3 +43,7 @@ jspm_packages
 
 # We need to include this folders, because they are mocks for integration tests
 !tests/**/node_modules
+
+.vscode
+.idea
+**/node_modules

src/preprocessor.ts

@@ -9,46 +9,51 @@ declare const global: any;
 
 const root = getPackageRoot();
 const {
-  testRegex,
-  collectCoverage,
-  coverageDirectory,
-  coverageReporters,
-  collectCoverageFrom,
-  testResultsProcessor
+    testRegex,
+    collectCoverage,
+    coverageDirectory,
+    coverageReporters,
+    collectCoverageFrom,
+    testResultsProcessor
 } = getJestConfig(root);
 
 //setting up cache to global object to resultprocessor consume
 if (testResultsProcessor) {
-  global.__ts_coverage__cache__ = {};
-  global.__ts_coverage__cache__.sourceCache = {};
-  global.__ts_coverage__cache__.coverageConfig = { collectCoverage, coverageDirectory, coverageReporters };
-  global.__ts_coverage__cache__.coverageCollectFiles =
-    collectCoverage &&
-    testResultsProcessor &&
-    collectCoverageFrom &&
-    collectCoverageFrom.length ?
-    glob.sync(collectCoverageFrom).map(x => nodepath.resolve(root, x)) : [];
+    global.__ts_coverage__cache__ = {};
+    global.__ts_coverage__cache__.sourceCache = {};
+    global.__ts_coverage__cache__.coverageConfig = { collectCoverage, coverageDirectory, coverageReporters };
+    global.__ts_coverage__cache__.coverageCollectFiles =
+        collectCoverage &&
+            testResultsProcessor &&
+            collectCoverageFrom &&
+            collectCoverageFrom.length ?
+            glob.sync(collectCoverageFrom).map(x => nodepath.resolve(root, x)) : [];
 }
 
 export function process(src, path, config) {
-  if (path.endsWith('.ts') || path.endsWith('.tsx')) {
-    const transpiled = tsc.transpileModule(
-      src,
-      {
-        compilerOptions: getTSConfig(config.globals, collectCoverage),
-        fileName: path
-      });
-
-    //store transpiled code contains source map into cache, except test cases
-    if (global.__ts_coverage__cache__) {
-      if (!testRegex || !path.match(testRegex)) {
-        global.__ts_coverage__cache__.sourceCache[path] = transpiled.outputText;
-      }
-    }
+    if (path.endsWith('.ts') || path.endsWith('.tsx')) {
+        const transpiled = tsc.transpileModule(
+            src,
+            {
+                compilerOptions: getTSConfig(config.globals, collectCoverage),
+                fileName: path
+            });
+
+        //store transpiled code contains source map into cache, except test cases
+        if (global.__ts_coverage__cache__) {
+            if (!testRegex || !path.match(testRegex)) {
+                global.__ts_coverage__cache__.sourceCache[path] = transpiled.outputText;
+            }
+        }
+
+        const start = transpiled.outputText.length > 12 ? transpiled.outputText.substr(1, 10) : '';
 
-    const modified = `require('ts-jest').install();${transpiled.outputText}`;
-    return modified;
-  }
+        const modified = start === 'use strict'
+            ? `'use strict';require('ts-jest').install();${transpiled.outputText}`
+            : `require('ts-jest').install();${transpiled.outputText}`;
+
+        return modified;
+    }
 
-  return src;
+    return src;
 }

tests/__tests__/use-strict.spec.ts

@@ -0,0 +1,27 @@
+import { } from 'jest';
+import { } from 'node';
+import runJest from '../__helpers__/runJest';
+
+describe('use strict', () => {
+
+  it('should show the error locations for "use strict" violations', () => {
+
+    const result = runJest('../use-strict', ['--no-cache', '-t', 'Invalid Strict']);
+
+    const stderr = result.stderr.toString();
+
+    expect(result.status).toBe(1);
+    expect(stderr).toContain('Strict.ts:4:4');
+    expect(stderr).toContain('Strict.test.ts:9:5');
+
+  });
+
+  it('should work with "use strict"', () => {
+
+    const result = runJest('../use-strict', ['--no-cache', '-t', 'Valid Strict']);
+
+    expect(result.status).toBe(0);
+
+  });
+
+});

tests/use-strict/Strict-valid.ts

@@ -0,0 +1,5 @@
+'use strict';
+
+export function checkStrictValid() {
+  var v = 33;
+}

tests/use-strict/Strict.ts

@@ -0,0 +1,5 @@
+'use strict';
+
+export function checkStrict() {
+  v = 33;
+};

tests/use-strict/__tests__/Strict-valid.test.ts

@@ -0,0 +1,13 @@
+declare var jest, describe, it, expect;
+
+import { checkStrictValid } from '../Strict-valid';
+
+describe('Valid Strict', () => {
+
+  it('should not throw an error', () => {
+
+    checkStrictValid();
+
+  });
+
+});

tests/use-strict/__tests__/Strict.test.ts

@@ -0,0 +1,13 @@
+declare var jest, describe, it, expect;
+
+import { checkStrict } from '../Strict';
+
+describe('Invalid Strict', () => {
+
+  it('should throw an error on line 9', () => {
+
+    checkStrict();
+
+  });
+
+});

tests/use-strict/package.json

@@ -0,0 +1,14 @@
+{
+  "jest": {
+    "transform": {
+      ".(ts|tsx)": "../../preprocessor.js"
+    },
+    "testResultsProcessor": "../../coverageprocessor.js",
+    "testRegex": "(/__tests__/.*|\\.(test|spec))\\.(ts|tsx|js)$",
+    "moduleFileExtensions": [
+      "ts",
+      "tsx",
+      "js"
+    ]
+  }
+}

tests/use-strict/tsconfig.json

@@ -0,0 +1,10 @@
+{
+  "compilerOptions": {
+    "target": "ES5",
+    "module": "commonjs",
+    "moduleResolution": "node",
+    "noEmitOnError": false,
+    "jsx": "react",
+    "allowJs": true
+  }
+}