Generate Jest config with custom TypeScript target

Author: maxdavidson

.gitignore

@@ -1,6 +1,6 @@
 # Created by https://www.gitignore.io/api/node,visualstudiocode,macos
 
-# Generated dirs
+# Generated stuff
 .code
 dist
 lib

.vscode/launch.json

@@ -12,7 +12,7 @@
       "--no-cache",
       "--runInBand",
       "--env=node-debug",
-      "--config=jest.config.json"
+      "--config=$(node jest.config.js)"
     ],
     "skipFiles": [
       "<node_internals>/**/*.js",

jest.config.js

@@ -0,0 +1,44 @@
+#!/usr/bin/env node
+var semver = require('semver');
+
+function getSupportedTypescriptTarget() {
+  var nodeVersion = process.versions.node;
+
+  if (semver.gt(nodeVersion, '7.6.0')) {
+    return 'es2017'
+  } else if (semver.gt(nodeVersion, '7.0.0')) {
+    return 'es2016';
+  } else if (semver.gt(nodeVersion, '6.0.0')) {
+    return 'es2015';
+  } else if (semver.gt(nodeVersion, '4.0.0')) {
+    return 'es5';
+  } else {
+    return 'es3';
+  }
+}
+
+var jestConfig = {
+  transform: {
+    ".(ts|tsx)": "<rootDir>/node_modules/ts-jest/preprocessor.js"
+  },
+  testResultsProcessor: "<rootDir>/node_modules/ts-jest/coverageprocessor.js",
+  testRegex: "(/__tests__/.*|\\.(test|spec))\\.(ts|tsx|js)$",
+  testPathIgnorePatterns: [
+    "<rootDir>[/\\\\](dist|coverage|node_modules)[/\\\\]",
+    "_\\w*.\\w+$"
+  ],
+  moduleFileExtensions: ["ts", "tsx", "js"],
+  globals: {
+    __TS_CONFIG__: {
+      target: getSupportedTypescriptTarget(),
+      inlineSourceMap: true
+    }
+  }
+};
+
+module.exports = jestConfig;
+
+// If this file is run as an executable, print the config stringified to JSON
+if (require.main === module) {
+  console.log(JSON.stringify(jestConfig));
+}

jest.config.json

@@ -17,8 +17,8 @@
     "clean": "rimraf dist es lib coverage",
     "typecheck": "tsc --noEmit",
     "lint": "tslint --project tsconfig.json --type-check --format stylish",
-    "test": "jest --config jest.config.json --coverage --no-cache",
-    "test:watch": "jest --config jest.config.json --watch --updateSnapshot",
+    "test": "jest --coverage --no-cache --config $(node jest.config.js)",
+    "test:watch": "jest --watch --updateSnapshot --config $(node jest.config.js)",
     "prepare": "npm run build",
     "prebuild": "npm run clean",
     "postbuild": "rimraf {lib,es}/**/__tests__",
@@ -46,7 +46,7 @@
     "dts-bundle": "^0.7.2",
     "jest": "^19.0.2",
     "jest-environment-node-debug": "^2.0.0",
-    "pascal-case": "^2.0.0",
+    "pascal-case": "^2.0.1",
     "rimraf": "^2.6.1",
     "rollup": "^0.41.6",
     "rollup-plugin-commonjs": "^8.0.2",
@@ -55,7 +55,8 @@
     "rollup-plugin-node-resolve": "^2.0.0",
     "rollup-plugin-sourcemaps": "^0.4.1",
     "rollup-plugin-uglify": "^1.0.1",
-    "ts-jest": "^19.0.1",
+    "semver": "^5.3.0",
+    "ts-jest": "^19.0.2",
     "tslint": "^4.5.1",
     "typescript": "^2.2.1"
   }