feat(babel): pass rollup context as this context into override config function (#784)

* pass rollup context as this context into override config function

* PR Review improvements

Author: KingSora

packages/babel/src/transformCode.js

@@ -18,7 +18,7 @@ export default async function transformCode(
 
   let transformOptions = !overrides.config
     ? config.options
-    : await overrides.config.call(this, config, {
+    : await overrides.config.call(ctx, config, {
         code: inputCode,
         customOptions
       });

packages/babel/test/as-input-plugin.js

@@ -374,9 +374,17 @@ test('works with minified bundled helpers', async (t) => {
 });
 
 test('supports customizing the loader', async (t) => {
+  const expectedRollupContextKeys = ['getCombinedSourcemap', 'getModuleIds', 'emitFile', 'resolve'];
   const customBabelPlugin = createBabelInputPluginFactory(() => {
     return {
       config(cfg) {
+        t.true(typeof this === 'object', 'override config this context is rollup context');
+        expectedRollupContextKeys.forEach((key) => {
+          t.true(
+            Object.keys(this).includes(key),
+            `override config this context is rollup context with key ${key}`
+          );
+        });
         return {
           ...cfg.options,
           plugins: [
@@ -387,6 +395,13 @@ test('supports customizing the loader', async (t) => {
         };
       },
       result(result) {
+        t.true(typeof this === 'object', 'override result this context is rollup context');
+        expectedRollupContextKeys.forEach((key) => {
+          t.true(
+            Object.keys(this).includes(key),
+            `override result this context is rollup context with key ${key}`
+          );
+        });
         return {
           ...result,
           code: `${result.code}\n// Generated by some custom loader`

packages/babel/test/as-output-plugin.js

@@ -266,9 +266,17 @@ export default getResult;
 });
 
 test('supports customizing the loader', async (t) => {
+  const expectedRollupContextKeys = ['getModuleIds', 'emitFile', 'resolve', 'parse'];
   const customBabelPlugin = createBabelOutputPluginFactory(() => {
     return {
       config(cfg) {
+        t.true(typeof this === 'object', 'override config this context is rollup context');
+        expectedRollupContextKeys.forEach((key) => {
+          t.true(
+            Object.keys(this).includes(key),
+            `override config this context is rollup context with key ${key}`
+          );
+        });
         return Object.assign({}, cfg.options, {
           plugins: [
             ...(cfg.options.plugins || []),
@@ -279,6 +287,13 @@ test('supports customizing the loader', async (t) => {
         });
       },
       result(result) {
+        t.true(typeof this === 'object', 'override result this context is rollup context');
+        expectedRollupContextKeys.forEach((key) => {
+          t.true(
+            Object.keys(this).includes(key),
+            `override result this context is rollup context with key ${key}`
+          );
+        });
         return Object.assign({}, result, {
           code: `${result.code}\n// Generated by some custom loader`
         });

packages/babel/types/index.d.ts

@@ -1,4 +1,4 @@
-import { Plugin } from 'rollup';
+import { Plugin, PluginContext, TransformPluginContext } from 'rollup';
 import { FilterPattern } from '@rollup/pluginutils';
 import * as babelCore from '@babel/core';
 
@@ -52,28 +52,45 @@ export type RollupBabelCustomOutputPluginOptions = (
   customOptions: Record<string, any>;
   pluginOptions: RollupBabelOutputPluginOptions;
 };
-export type RollupBabelCustomPluginConfig = (
+export interface RollupBabelCustomPluginConfigOptions {
+  code: string;
+  customOptions: Record<string, any>;
+}
+export interface RollupBabelCustomPluginResultOptions {
+  code: string;
+  customOptions: Record<string, any>;
+  config: babelCore.PartialConfig;
+  transformOptions: babelCore.TransformOptions;
+}
+export type RollupBabelCustomInputPluginConfig = (
+  this: TransformPluginContext,
+  cfg: babelCore.PartialConfig,
+  options: RollupBabelCustomPluginConfigOptions
+) => babelCore.TransformOptions;
+export type RollupBabelCustomInputPluginResult = (
+  this: TransformPluginContext,
+  result: babelCore.BabelFileResult,
+  options: RollupBabelCustomPluginResultOptions
+) => babelCore.BabelFileResult;
+export type RollupBabelCustomOutputPluginConfig = (
+  this: PluginContext,
   cfg: babelCore.PartialConfig,
-  options: { code: string; customOptions: Record<string, any> }
+  options: RollupBabelCustomPluginConfigOptions
 ) => babelCore.TransformOptions;
-export type RollupBabelCustomPluginResult = (
+export type RollupBabelCustomOutputPluginResult = (
+  this: PluginContext,
   result: babelCore.BabelFileResult,
-  options: {
-    code: string;
-    customOptions: Record<string, any>;
-    config: babelCore.PartialConfig;
-    transformOptions: babelCore.TransformOptions;
-  }
+  options: RollupBabelCustomPluginResultOptions
 ) => babelCore.BabelFileResult;
 export interface RollupBabelCustomInputPlugin {
   options?: RollupBabelCustomInputPluginOptions;
-  config?: RollupBabelCustomPluginConfig;
-  result?: RollupBabelCustomPluginResult;
+  config?: RollupBabelCustomInputPluginConfig;
+  result?: RollupBabelCustomInputPluginResult;
 }
 export interface RollupBabelCustomOutputPlugin {
   options?: RollupBabelCustomOutputPluginOptions;
-  config?: RollupBabelCustomPluginConfig;
-  result?: RollupBabelCustomPluginResult;
+  config?: RollupBabelCustomOutputPluginConfig;
+  result?: RollupBabelCustomOutputPluginResult;
 }
 export type RollupBabelCustomInputPluginBuilder = (
   babel: typeof babelCore