From a1fd26f8c8e06787f369e99e8676abd95bfa08cd Mon Sep 17 00:00:00 2001
From: Sascha Tandel <s.tandel@kenoxa.de>
Date: Wed, 6 Nov 2019 18:13:02 +0100
Subject: [PATCH] feat: allow to opt-out of default babel plugins and presets

---
 README.md                                     |  8 +++++
 src/plugin/i-typescript-plugin-options.ts     |  1 +
 src/plugin/typescript-plugin.ts               |  1 +
 .../get-babel-config-options.ts               |  2 ++
 src/util/get-babel-config/get-babel-config.ts | 36 +++++++++++++++++++
 src/util/plugin-options/get-plugin-options.ts |  1 +
 6 files changed, 49 insertions(+)

diff --git a/README.md b/README.md
index 268becb2..43d5630a 100644
--- a/README.md
+++ b/README.md
@@ -442,6 +442,12 @@ Type: `string | Partial<IBabelInputOptions>`
 
 This option will only be respected when `"babel"` is being used as the `transpiler` and can be used to provide a [Babel config](https://babeljs.io/docs/en/options) or a path to one.
 
+#### `noBabelConfigCustomization`
+
+Type: `boolean`
+
+If this option is `true`, **no** [default presets or plugins](#default-babel-plugins) are applied to the babel config. The [ignored/overridden Babel options](#ignoredoverridden-babel-options) are nevertheless applied.
+
 #### `tsconfig`
 
 Type: `string | Partial<CompilerOptions> | Partial<Record<keyof CompilerOptions, string | number | boolean>> | ParsedCommandLine | TsConfigResolver | TsConfigResolverWithFileName`
@@ -550,6 +556,8 @@ By default, the plugin will conditionally apply the `@babel/preset-env` preset i
 
 If you provide these presets or plugins yourself through the found or provided Babel config, _your_ config options will take precedence.
 
+In case that this is not enough for you setting [`noBabelConfigCustomization`](#nobabelconfigcustomization) disables these defaults.
+
 Here's table with a full overview of the specifics:
 
 | Preset/Plugin                                      | Condition                                                                                                              | Reason                                                                                                                                                                                                                                                                                                                                                                                                   |
diff --git a/src/plugin/i-typescript-plugin-options.ts b/src/plugin/i-typescript-plugin-options.ts
index e9708060..481b5ff0 100644
--- a/src/plugin/i-typescript-plugin-options.ts
+++ b/src/plugin/i-typescript-plugin-options.ts
@@ -54,6 +54,7 @@ export interface ITypescriptPluginTypescriptOptions extends ITypescriptPluginBas
 
 export interface ITypescriptPluginBabelOptions extends ITypescriptPluginBaseOptions {
 	transpiler: "babel";
+	noBabelConfigCustomization?: boolean;
 	babelConfig?: string | Partial<IBabelInputOptions>;
 }
 
diff --git a/src/plugin/typescript-plugin.ts b/src/plugin/typescript-plugin.ts
index bee3154a..52f22444 100644
--- a/src/plugin/typescript-plugin.ts
+++ b/src/plugin/typescript-plugin.ts
@@ -189,6 +189,7 @@ export default function typescriptRollupPlugin(pluginInputOptions: Partial<Types
 				const babelConfigResult = getBabelConfig({
 					cwd,
 					babelConfig: pluginOptions.babelConfig,
+					noBabelConfigCustomization: pluginOptions.noBabelConfigCustomization,
 					forcedOptions: getForcedBabelOptions({cwd, pluginOptions, rollupInputOptions, browserslist: computedBrowserslist}),
 					defaultOptions: getDefaultBabelOptions({pluginOptions, rollupInputOptions, browserslist: computedBrowserslist}),
 					browserslist: computedBrowserslist,
diff --git a/src/util/get-babel-config/get-babel-config-options.ts b/src/util/get-babel-config/get-babel-config-options.ts
index 09fc3c71..a288f3f2 100644
--- a/src/util/get-babel-config/get-babel-config-options.ts
+++ b/src/util/get-babel-config/get-babel-config-options.ts
@@ -1,3 +1,4 @@
+import {ITypescriptPluginBabelOptions} from "../../plugin/i-typescript-plugin-options";
 import {IGetForcedBabelOptionsResult} from "../get-forced-babel-options/i-get-forced-babel-options-result";
 import {IGetDefaultBabelOptionsResult} from "../get-default-babel-options/i-get-default-babel-options-result";
 import {InputOptions} from "rollup";
@@ -8,4 +9,5 @@ export interface GetBabelConfigOptions extends FindBabelConfigOptions {
 	rollupInputOptions: InputOptions;
 	forcedOptions?: IGetForcedBabelOptionsResult;
 	defaultOptions?: IGetDefaultBabelOptionsResult;
+	noBabelConfigCustomization?: ITypescriptPluginBabelOptions["noBabelConfigCustomization"];
 }
diff --git a/src/util/get-babel-config/get-babel-config.ts b/src/util/get-babel-config/get-babel-config.ts
index f091f4d5..04b5edb1 100644
--- a/src/util/get-babel-config/get-babel-config.ts
+++ b/src/util/get-babel-config/get-babel-config.ts
@@ -99,6 +99,7 @@ function configItemIsAllowedDuringNoMinification({file: {resolved}}: IBabelConfi
 export function getBabelConfig({
 	babelConfig,
 	cwd,
+	noBabelConfigCustomization,
 	forcedOptions = {},
 	defaultOptions = {},
 	browserslist,
@@ -106,6 +107,41 @@ export function getBabelConfig({
 }: GetBabelConfigOptions): GetBabelConfigResult {
 	const resolvedConfig = findBabelConfig({cwd, babelConfig});
 
+	if (noBabelConfigCustomization === true) {
+		return {
+			config: filename => {
+				const partialConfig =
+					resolvedConfig != null && resolvedConfig.kind === "dict"
+						? // If the given babelConfig is an object of input options, use that as the basis for the full config
+						  resolvedConfig
+						: // Load the path to a babel config provided to the plugin if any, otherwise try to resolve it
+						  loadPartialConfig({
+								cwd,
+								root: cwd,
+								...(resolvedConfig != null ? {configFile: resolvedConfig.path} : {babelrc: true}),
+								filename
+						  });
+
+				const {options} = loadPartialConfig({
+					...partialConfig.options,
+					...forcedOptions,
+					presets: partialConfig.options.presets || [],
+					plugins: partialConfig.options.plugins || [],
+					filename
+				});
+
+				// sourceMap is an alias for 'sourceMaps'. If the user provided it, make sure it is undefined. Otherwise, Babel will fail during validation
+				if ("sourceMap" in options) {
+					delete options.sourceMap;
+				}
+
+				return options;
+			},
+			minifyConfig: undefined,
+			hasMinifyOptions: false
+		};
+	}
+
 	// Load a partial Babel config based on the input options
 	const partialConfig = loadPartialConfig(
 		resolvedConfig != null && resolvedConfig.kind === "dict"
diff --git a/src/util/plugin-options/get-plugin-options.ts b/src/util/plugin-options/get-plugin-options.ts
index 99ed164a..8cea847f 100644
--- a/src/util/plugin-options/get-plugin-options.ts
+++ b/src/util/plugin-options/get-plugin-options.ts
@@ -44,6 +44,7 @@ export function getPluginOptions(options: Partial<TypescriptPluginOptions>): Typ
 		return {
 			...baseOptions,
 			...("babelConfig" in options ? {babelConfig: options.babelConfig} : {}),
+			...("noBabelConfigCustomization" in options ? {noBabelConfigCustomization: options.noBabelConfigCustomization} : {}),
 			transpiler: "babel"
 		};
 	}