With replace

Author: schmidt-sebastian

packages/firestore/rollup.config.js

@@ -102,14 +102,16 @@ export function resolveMemoryExterns(deps, externsId, referencedBy) {
 const es5BuildPlugins = [
   typescriptPlugin({
     typescript,
-    tsconfigOverride: {
-      compilerOptions: {
-        allowJs: true
-      }
-    },
-    include: ["*.js", "**/*.js"],
+    transformers: appendPrivatePrefixTransformers,
+    cacheRoot: `./.cache/es5.mangled/`
   }),
-  sourcemaps()
+  {
+    transform(code, id) {
+      return code.replace(/\/\*\* @class \*\//g, "\/*@__PURE__*\/");
+    }
+  },
+  json(),
+  terser(manglePrivatePropertiesOptions)
 ];
 
 const es2017BuildPlugins = [
@@ -120,14 +122,33 @@ const es2017BuildPlugins = [
         target: 'es2017'
       }
     },
-    cacheRoot: './.cache/browser/',
+    cacheRoot: './.cache/es2017.mangled/',
     transformers: appendPrivatePrefixTransformers
   }),
   json({ preferConst: true }),
   terser(manglePrivatePropertiesOptions)
 ];
 
 const browserBuilds = [
+  // ES5 ESM Build (with persistence)
+  {
+    input: 'index.ts',
+    output: { file: pkg.module, format: 'es', sourcemap: true },
+    plugins: es5BuildPlugins,
+    external: resolveBrowserExterns
+  },
+  // ES5 ESM Build (memory-only)
+  {
+    input: 'index.memory.ts',
+    output: {
+      file: path.resolve('./memory', memoryPkg.module),
+      format: 'es',
+      sourcemap: true
+    },
+    plugins: es5BuildPlugins,
+    external: (id, referencedBy) =>
+      resolveMemoryExterns(browserDeps, id, referencedBy)
+  },
   // ES2017 ESM build (with persistence)
   {
     input: 'index.ts',
@@ -151,41 +172,27 @@ const browserBuilds = [
     external: (id, referencedBy) =>
       resolveMemoryExterns(browserDeps, id, referencedBy)
   },
-  // ES5 ESM Build (with persistence)
-  //
-  // This and all following builds are based on the mangling and tree-shaking
-  // in the ESM2017 build, since the ESM2017 build results in improved tree
-  // shaking and property name mangling.
-  {
-    input: pkg.esm2017,
-    output: { file: pkg.module, format: 'es', sourcemap: true },
-    plugins: es5BuildPlugins
-  },
-  // ES5 ESM Build (memory-only)
-  {
-    input: path.resolve('./memory', memoryPkg.esm2017),
-    output: {
-      file: path.resolve('./memory', memoryPkg.module),
-      format: 'es',
-      sourcemap: true
-    },
-    plugins: es5BuildPlugins
-  },
   // ES5 CJS Build (with persistence)
+  //
+  // This build is based on the mangling in the ESM build above, since
+  // Terser's Property name mangling doesn't work well with CJS's syntax.
   {
-    input: pkg.esm2017,
+    input: pkg.module,
     output: { file: pkg.browser, format: 'cjs', sourcemap: true },
-    plugins: es5BuildPlugins
+    plugins: [sourcemaps()]
   },
   // ES5 CJS Build (memory-only)
+  //
+  // This build is based on the mangling in the ESM build above, since
+  // Terser's Property name mangling doesn't work well with CJS's syntax.
   {
-    input: path.resolve('./memory', memoryPkg.esm2017),
+    input: path.resolve('./memory', memoryPkg.module),
     output: {
       file: path.resolve('./memory', memoryPkg.browser),
       format: 'cjs',
       sourcemap: true
     },
-    plugins: es5BuildPlugins
+    plugins: [sourcemaps()]
   }
 ];