feat: respect devtool values for source map generation (#140)

README.md

@@ -284,13 +284,16 @@ module.exports = {
 Type: `Boolean`
 Default: `false`
 
-**Only works with `source-map`, `inline-source-map`, `hidden-source-map` and `nosources-source-map` values for the [`devtool`](https://webpack.js.org/configuration/devtool/) option.**
+**Works only with `source-map`, `inline-source-map`, `hidden-source-map` and `nosources-source-map` values for the [`devtool`](https://webpack.js.org/configuration/devtool/) option.**
 
 Why?
 
 - `eval` wraps modules in `eval("string")` and the minimizer does not handle strings.
 - `cheap` has not column information and minimizer generate only a single line, which leave only a single mapping.
 
+The plugin respect the [`devtool`](https://webpack.js.org/configuration/devtool/).
+Using supported `devtool` values enable source map generation.
+
 Use source maps to map error message locations to modules (this slows down the compilation).
 If you use your own `minify` function please read the `minify` section for handling source maps correctly.
 

src/index.js

@@ -28,7 +28,7 @@ class TerserPlugin {
       chunkFilter = () => true,
       warningsFilter = () => true,
       extractComments = true,
-      sourceMap = false,
+      sourceMap,
       cache = true,
       cacheKeys = (defaultCacheKeys) => defaultCacheKeys,
       parallel = true,
@@ -155,6 +155,14 @@ class TerserPlugin {
   }
 
   apply(compiler) {
+    this.options.sourceMap =
+      typeof this.options.sourceMap === 'undefined'
+        ? compiler.options.devtool &&
+          /^((inline|hidden|nosources)-)?source-?map/.test(
+            compiler.options.devtool
+          )
+        : Boolean(this.options.sourceMap);
+
     const buildModuleFn = (moduleArg) => {
       // to get detailed location info about errors
       // eslint-disable-next-line no-param-reassign