feat: Implement unit testing with bundle (#835)

* feat: Implement unit testing with bundle

NativeScript/nativescript-cli#4392

* chore: share the regex for `root|page` between bundle-config loader and unit-testing config loader

Author: Fatme

Diff for: bundle-config-loader.js

@@ -1,6 +1,14 @@
+const unitTestingConfigLoader = require("./unit-testing-config-loader");
+
 module.exports = function (source) {
     this.cacheable();
-    const { angular = false, loadCss = true, registerModules = /(root|page)\.(xml|css|js|ts|scss)$/ } = this.query;
+    const { angular = false, loadCss = true, unitTesting, projectRoot, appFullPath, registerModules = /(root|page)\.(xml|css|js|ts|scss)$/ } = this.query;
+
+    if (unitTesting) {
+        source = unitTestingConfigLoader({ appFullPath, projectRoot, angular, rootPagesRegExp: registerModules });
+        this.callback(null, source);
+        return;
+    }
 
     const hmr = `
         if (module.hot) {

Diff for: templates/webpack.angular.js

@@ -47,6 +47,7 @@ module.exports = env => {
         report, // --env.report
         sourceMap, // --env.sourceMap
         hmr, // --env.hmr,
+        unitTesting, // --env.unitTesting
     } = env;
 
     const externals = nsWebpack.getConvertedExternals(env.externals);
@@ -192,6 +193,9 @@ module.exports = env => {
                             options: {
                                 angular: true,
                                 loadCss: !snapshot, // load the application css if in debug mode
+                                unitTesting,
+                                appFullPath,
+                                projectRoot,
                             }
                         },
                     ].filter(loader => !!loader)

Diff for: templates/webpack.javascript.js

@@ -42,6 +42,7 @@ module.exports = env => {
         report, // --env.report
         sourceMap, // --env.sourceMap
         hmr, // --env.hmr,
+        unitTesting, // --env.unitTesting
     } = env;
     const externals = nsWebpack.getConvertedExternals(env.externals);
 
@@ -153,6 +154,9 @@ module.exports = env => {
                             loader: "nativescript-dev-webpack/bundle-config-loader",
                             options: {
                                 loadCss: !snapshot, // load the application css if in debug mode
+                                unitTesting,
+                                appFullPath,
+                                projectRoot,
                             }
                         },
                     ].filter(loader => !!loader)

Diff for: templates/webpack.typescript.js

@@ -42,6 +42,7 @@ module.exports = env => {
         report, // --env.report
         sourceMap, // --env.sourceMap
         hmr, // --env.hmr,
+        unitTesting, // --env.unitTesting
     } = env;
     const externals = nsWebpack.getConvertedExternals(env.externals);
 
@@ -155,6 +156,9 @@ module.exports = env => {
                             loader: "nativescript-dev-webpack/bundle-config-loader",
                             options: {
                                 loadCss: !snapshot, // load the application css if in debug mode
+                                unitTesting,
+                                appFullPath,
+                                projectRoot,
                             }
                         },
                     ].filter(loader => !!loader)

Diff for: templates/webpack.vue.js

@@ -46,6 +46,7 @@ module.exports = env => {
         report, // --env.report
         hmr, // --env.hmr
         sourceMap, // --env.sourceMap
+        unitTesting, // --env.unitTesting
     } = env;
 
     const externals = nsWebpack.getConvertedExternals(env.externals);
@@ -167,6 +168,9 @@ module.exports = env => {
                             options: {
                                 registerPages: true, // applicable only for non-angular apps
                                 loadCss: !snapshot, // load the application css if in debug mode
+                                unitTesting,
+                                appFullPath,
+                                projectRoot,
                             },
                         },
                     ].filter(loader => Boolean(loader)),

Diff for: unit-testing-config-loader.js

@@ -0,0 +1,33 @@
+const { join, relative } = require("path");
+
+module.exports = function ({ appFullPath, projectRoot, angular, rootPagesRegExp }) {
+    // TODO: Consider to use the files property from karma.conf.js
+    const testFilesRegExp = /tests\/.*\.js/;
+    const runnerFullPath = join(projectRoot, "node_modules", "nativescript-unit-test-runner");
+    const runnerRelativePath = relative(appFullPath, runnerFullPath);
+    let source = `
+        require("tns-core-modules/bundle-entry-points");
+        const runnerContext = require.context("${runnerRelativePath}", true, ${rootPagesRegExp});
+        global.registerWebpackModules(runnerContext);
+    `;
+
+    if (angular) {
+        source += `
+            const context = require.context("~/", true, ${testFilesRegExp});
+            global.registerWebpackModules(context);
+        `;
+    } else {
+        const registerModules = new RegExp(`(${rootPagesRegExp.source})|(${testFilesRegExp.source})`);
+        source += `
+            const context = require.context("~/", true, ${registerModules});
+            global.registerWebpackModules(context);
+        `;
+    }
+
+    const runnerEntryPointPath = join(runnerRelativePath, "bundle-app.js");
+    source += `
+        require("${runnerEntryPointPath}");
+    `;
+
+    return source;
+}