Better docs

Author: schmidt-sebastian

packages/firestore/rollup.config.es.js

@@ -26,6 +26,11 @@ import { resolveNodeExterns, resolveBrowserExterns } from './rollup.shared';
 import pkg from './package.json';
 import memoryPkg from './memory/package.json';
 
+// This file defines the second rollup pipeline and transpiles the ES2017 SDK
+// into ES3 code. By splitting the build process into two independent build
+// pipelines, we take advantage of tree shaking in ES2017 builds even for
+// language levels that don't support tree shaking.
+
 const browserPlugins = [
   typescriptPlugin({
     typescript,
@@ -45,6 +50,25 @@ const browserPlugins = [
   sourcemaps()
 ];
 
+const nodePlugins = [
+  typescriptPlugin({
+    typescript,
+    compilerOptions: {
+      allowJs: true,
+      importHelpers: true
+    },
+    include: ['dist/*.js']
+  }),
+  terser({
+    output: {
+      comments: 'all',
+      beautify: true
+    },
+    mangle: false
+  }),
+  sourcemaps()
+];
+
 const browserBuilds = [
   {
     input: pkg.esm2017,
@@ -80,25 +104,6 @@ const browserBuilds = [
   }
 ];
 
-const nodePlugins = [
-  typescriptPlugin({
-    typescript,
-    compilerOptions: {
-      allowJs: true,
-      importHelpers: true
-    },
-    include: ['dist/*.js']
-  }),
-  terser({
-    output: {
-      comments: 'all',
-      beautify: true
-    },
-    mangle: false
-  }),
-  sourcemaps()
-];
-
 const nodeBuilds = [
   {
     input: pkg.mainES2017,

packages/firestore/rollup.config.es2017.js

@@ -36,7 +36,7 @@ import {
   nodeDeps
 } from './rollup.shared';
 
-// This Firestore Rollup configuration provides a number of different builds:
+// Firestore is released in a number of different build configurations:
 // - Browser builds that support persistence in ES5 CJS and ES5 ESM formats and
 //   ES2017 in ESM format.
 // - In-memory Browser builds that support persistence in ES5 CJS and ES5 ESM
@@ -48,6 +48,10 @@ import {
 // The in-memory builds are roughly 130 KB smaller, but throw an exception
 // for calls to `enablePersistence()` or `clearPersistence()`.
 //
+// We use two different rollup pipelines to take advantage of tree shaking in
+// the ES2017 builds. The build pipeline in this file produces ES2017 builds
+// that are consumed by `rollup.config.es.js`.
+//
 // All browser builds rely on Terser's property name mangling to reduce code
 // size.
 //