fix: rollup configuration (#835)

This is a full refactoring of the rollup configuration to speed up builds, simplify the configuration prevent warnings and fix an error with the generated source maps.

In detail:
 - refactor: Combine the three non-esm outputs into a single configuration.

 - feat: Enabled source-maps for all build outputs.

 - fix: Use a separate TypeScript configuration (`tsconfig.build.json`) during build. This configuration only compiles the required typescript files and doesn't reproduce the directory structure in the dist-folder (see also the change in package.json). It also now generates source maps correctly (#834).

 - chore: Moved `fast-deep-equal` from dependencies to devDependencies. It is a very small function, and it has always been bundled in all of our outputs, so it's not actually required at runtime. This will be changed in the next major release.

 fixes #834

package.json

@@ -20,7 +20,7 @@
   "main": "dist/index.umd.js",
   "unpkg": "dist/index.min.js",
   "module": "dist/index.mjs",
-  "types": "dist/src/index.d.ts",
+  "types": "dist/index.d.ts",
   "files": [
     "dist/",
     "src/"
@@ -33,9 +33,7 @@
     "test": "jest src/*",
     "test:e2e": "jest e2e/*"
   },
-  "dependencies": {
-    "fast-deep-equal": "^3.1.3"
-  },
+  "dependencies": {},
   "devDependencies": {
     "@babel/preset-env": "^7.9.5",
     "@babel/runtime-corejs3": "^7.9.2",
@@ -54,6 +52,7 @@
     "eslint-config-prettier": "^9.0.0",
     "eslint-plugin-jest": "^27.4.0",
     "eslint-plugin-prettier": "^5.0.0",
+    "fast-deep-equal": "^3.1.3",
     "geckodriver": "^4.2.1",
     "jest": "^29.7.0",
     "jest-environment-jsdom": "^29.7.0",

rollup.config.mjs

@@ -20,71 +20,55 @@ import { nodeResolve } from "@rollup/plugin-node-resolve";
 import terser from "@rollup/plugin-terser";
 import typescript from "@rollup/plugin-typescript";
 
-const babelOptions = {
-  extensions: [".js", ".ts"],
-};
-
-const terserOptions = { output: { comments: "" } };
-
-const resolveOptions = {
-  mainFields: ["browser", "jsnext:main", "module", "main"],
+const terserOptions = {
+  output: { comments: "some" },
 };
 
 export default [
+  // UMD and browser (iife) builds
   {
     input: "src/index.ts",
     plugins: [
-      typescript({ tsconfig: "./tsconfig.json", declarationDir: "./" }),
-
-      nodeResolve(resolveOptions),
+      typescript({ tsconfig: "./tsconfig.build.json", declarationDir: "./" }),
+      nodeResolve({
+        mainFields: ["browser", "jsnext:main", "module", "main"],
+      }),
       commonjs(),
-      babel(babelOptions),
-      terser(terserOptions),
+      babel({
+        extensions: [".js", ".ts"],
+        babelHelpers: "bundled",
+      }),
     ],
-    output: {
-      file: "dist/index.umd.js",
-      format: "umd",
-      name: "google.maps.plugins.loader",
-      sourcemap: true,
-    },
-  },
-  {
-    input: "src/index.ts",
-    plugins: [
-      typescript({ tsconfig: "./tsconfig.json", declarationDir: "./" }),
-
-      nodeResolve(resolveOptions),
-      commonjs(),
-      babel(babelOptions),
-      terser(terserOptions),
+    output: [
+      {
+        file: "dist/index.umd.js",
+        format: "umd",
+        name: "google.maps.plugins.loader",
+        sourcemap: true,
+        plugins: [terser(terserOptions)],
+      },
+      {
+        file: "dist/index.min.js",
+        format: "iife",
+        name: "google.maps.plugins.loader",
+        sourcemap: true,
+        plugins: [terser(terserOptions)],
+      },
+      {
+        file: "dist/index.dev.js",
+        format: "iife",
+        name: "google.maps.plugins.loader",
+        sourcemap: true,
+      },
     ],
-    output: {
-      file: "dist/index.min.js",
-      format: "iife",
-      name: "google.maps.plugins.loader",
-    },
   },
-  {
-    input: "src/index.ts",
-    plugins: [
-      typescript({ tsconfig: "./tsconfig.json", declarationDir: "./" }),
 
-      nodeResolve(resolveOptions),
-      commonjs(),
-      babel(babelOptions),
-    ],
-    output: {
-      file: "dist/index.dev.js",
-      format: "iife",
-      name: "google.maps.plugins.loader",
-    },
-  },
+  // ESM build
   {
     input: "src/index.ts",
     plugins: [
-      typescript({ tsconfig: "./tsconfig.json", declarationDir: "./" }),
-
-      nodeResolve(resolveOptions),
+      typescript({ tsconfig: "./tsconfig.build.json", declarationDir: "./" }),
+      nodeResolve(),
       commonjs(),
     ],
     output: {

tsconfig.build.json

@@ -0,0 +1,6 @@
+{
+  "extends": "./tsconfig.json",
+  "compilerOptions": { "noEmit": false },
+  "include": ["src/**/*"],
+  "exclude": ["node_modules", "./dist", "./e2e", "src/**/*.test.ts"]
+}