Add additionalData option

README.md

@@ -45,13 +45,12 @@ And run `webpack` via your preferred method.
 
 ## Options
 
-|                  Name                   |         Type         |         Default          | Description                                      |
-| :-------------------------------------: | :------------------: | :----------------------: | :----------------------------------------------- |
-|    **[`lessOptions`](#lessoptions)**    | `{Object\|Function}` | `{ relativeUrls: true }` | Options for Less.                                |
-|    **[`prependData`](#prependdata)**    | `{String\|Function}` |       `undefined`        | Prepends Less code before the actual entry file. |
-|     **[`appendData`](#appenddata)**     | `{String\|Function}` |       `undefined`        | Prepends Less code after the actual entry file.  |
-|      **[`sourceMap`](#sourcemap)**      |     `{Boolean}`      |    `compiler.devtool`    | Enables/Disables generation of source maps.      |
-| **[`implementation`](#implementation)** |      `{Object}`      |          `less`          | Setup Less implementation to use.                |
+|                  Name                   |         Type         |         Default          | Description                                            |
+| :-------------------------------------: | :------------------: | :----------------------: | :----------------------------------------------------- |
+|    **[`lessOptions`](#lessoptions)**    | `{Object\|Function}` | `{ relativeUrls: true }` | Options for Less.                                      |
+| **[`additionalData`](#additionalData)** | `{String\|Function}` |       `undefined`        | Prepends/Appends `Less` code to the actual entry file. |
+|      **[`sourceMap`](#sourcemap)**      |     `{Boolean}`      |    `compiler.devtool`    | Enables/Disables generation of source maps.            |
+| **[`implementation`](#implementation)** |      `{Object}`      |          `less`          | Setup Less implementation to use.                      |
 
 ### `lessOptions`
 
@@ -134,12 +133,13 @@ module.exports = {
 };
 ```
 
-### `prependData`
+### `additionalData`
 
 Type: `String|Function`
 Default: `undefined`
 
 Prepends `Less` code before the actual entry file.
+In this case, the `less-loader` will not override the source but just **prepend** the entry's content.
 
 This is especially useful when some of your Less variables depend on the environment:
 
@@ -159,7 +159,7 @@ module.exports = {
           {
             loader: 'less-loader',
             options: {
-              prependData: `@env: ${process.env.NODE_ENV};`,
+              additionalData: `@env: ${process.env.NODE_ENV};`,
             },
           },
         ],
@@ -183,16 +183,16 @@ module.exports = {
           {
             loader: 'less-loader',
             options: {
-              prependData: (loaderContext) => {
+              additionalData: (content, loaderContext) => {
                 // More information about available properties https://webpack.js.org/api/loaders/
                 const { resourcePath, rootContext } = loaderContext;
                 const relativePath = path.relative(rootContext, resourcePath);
 
                 if (relativePath === 'styles/foo.less') {
-                  return '@value: 100px;';
+                  return '@value: 100px;' + content;
                 }
 
-                return '@value: 200px;';
+                return '@value: 200px;' + content;
               },
             },
           },
@@ -203,17 +203,6 @@ module.exports = {
 };
 ```
 
-### `appendData`
-
-Type: `String|Function`
-Default: `undefined`
-
-AppendData `Less` code after the actual entry file.
-
-This can be useful when you need to rewrite some of your Less variables.:
-
-> ℹ Since you're injecting code, this will break the source mappings in your entry file. Often there's a simpler solution than this, like multiple Less entry files.
-
 #### `String`
 
 ```js

src/index.js

@@ -24,18 +24,11 @@ function lessLoader(source) {
 
   let data = source;
 
-  if (typeof options.prependData !== 'undefined') {
+  if (typeof options.additionalData !== 'undefined') {
     data =
-      typeof options.prependData === 'function'
-        ? `${options.prependData(this)}\n${data}`
-        : `${options.prependData}\n${data}`;
-  }
-
-  if (typeof options.appendData !== 'undefined') {
-    data =
-      typeof options.appendData === 'function'
-        ? `${data}\n${options.appendData(this)}`
-        : `${data}\n${options.appendData}`;
+      typeof options.additionalData === 'function'
+        ? `${options.additionalData(data, this)}`
+        : `${options.additionalData}\n${data}`;
   }
 
   getLessImplementation(options.implementation)

src/options.json

@@ -13,19 +13,8 @@
         }
       ]
     },
-    "prependData": {
-      "description": "Prepends `Less` code before the actual entry file (https://github.com/webpack-contrib/less-loader#prependdata).",
-      "anyOf": [
-        {
-          "type": "string"
-        },
-        {
-          "instanceof": "Function"
-        }
-      ]
-    },
-    "appendData": {
-      "description": "Add `Less` code after the actual entry file (https://github.com/webpack-contrib/less-loader#postponeddata).",
+    "additionalData": {
+      "description": "Prepends/Appends `Less` code to the actual entry file (https://github.com/webpack-contrib/less-loader#additionalData).",
       "anyOf": [
         {
           "type": "string"

test/__snapshots__/additionalData-option.test.js.snap

@@ -0,0 +1,27 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`additionalData option should work additionalData data as function: css 1`] = `
+"/* RelativePath: additional-data.less; */
+.background {
+  color: coral;
+}
+.custom-class {
+  color: red;
+}
+"
+`;
+
+exports[`additionalData option should work additionalData data as function: errors 1`] = `Array []`;
+
+exports[`additionalData option should work additionalData data as function: warnings 1`] = `Array []`;
+
+exports[`additionalData option should work additionalData data as string: css 1`] = `
+".background {
+  color: coral;
+}
+"
+`;
+
+exports[`additionalData option should work additionalData data as string: errors 1`] = `Array []`;
+
+exports[`additionalData option should work additionalData data as string: warnings 1`] = `Array []`;

test/__snapshots__/validate-options.test.js.snap

@@ -1,63 +1,63 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`validate options should throw an error on the "appendData" option with "/test/" value 1`] = `
+exports[`validate options should throw an error on the "additionalData" option with "/test/" value 1`] = `
 "Invalid options object. Less Loader has been initialized using an options object that does not match the API schema.
- - options.appendData should be one of these:
+ - options.additionalData should be one of these:
    string | function
-   -> Add \`Less\` code after the actual entry file (https://github.com/webpack-contrib/less-loader#postponeddata).
+   -> Prepends/Appends \`Less\` code to the actual entry file (https://github.com/webpack-contrib/less-loader#additionalData).
    Details:
-    * options.appendData should be a string.
-    * options.appendData should be an instance of function."
+    * options.additionalData should be a string.
+    * options.additionalData should be an instance of function."
 `;
 
-exports[`validate options should throw an error on the "appendData" option with "[]" value 1`] = `
+exports[`validate options should throw an error on the "additionalData" option with "[]" value 1`] = `
 "Invalid options object. Less Loader has been initialized using an options object that does not match the API schema.
- - options.appendData should be one of these:
+ - options.additionalData should be one of these:
    string | function
-   -> Add \`Less\` code after the actual entry file (https://github.com/webpack-contrib/less-loader#postponeddata).
+   -> Prepends/Appends \`Less\` code to the actual entry file (https://github.com/webpack-contrib/less-loader#additionalData).
    Details:
-    * options.appendData should be a string.
-    * options.appendData should be an instance of function."
+    * options.additionalData should be a string.
+    * options.additionalData should be an instance of function."
 `;
 
-exports[`validate options should throw an error on the "appendData" option with "{}" value 1`] = `
+exports[`validate options should throw an error on the "additionalData" option with "{}" value 1`] = `
 "Invalid options object. Less Loader has been initialized using an options object that does not match the API schema.
- - options.appendData should be one of these:
+ - options.additionalData should be one of these:
    string | function
-   -> Add \`Less\` code after the actual entry file (https://github.com/webpack-contrib/less-loader#postponeddata).
+   -> Prepends/Appends \`Less\` code to the actual entry file (https://github.com/webpack-contrib/less-loader#additionalData).
    Details:
-    * options.appendData should be a string.
-    * options.appendData should be an instance of function."
+    * options.additionalData should be a string.
+    * options.additionalData should be an instance of function."
 `;
 
-exports[`validate options should throw an error on the "appendData" option with "1" value 1`] = `
+exports[`validate options should throw an error on the "additionalData" option with "1" value 1`] = `
 "Invalid options object. Less Loader has been initialized using an options object that does not match the API schema.
- - options.appendData should be one of these:
+ - options.additionalData should be one of these:
    string | function
-   -> Add \`Less\` code after the actual entry file (https://github.com/webpack-contrib/less-loader#postponeddata).
+   -> Prepends/Appends \`Less\` code to the actual entry file (https://github.com/webpack-contrib/less-loader#additionalData).
    Details:
-    * options.appendData should be a string.
-    * options.appendData should be an instance of function."
+    * options.additionalData should be a string.
+    * options.additionalData should be an instance of function."
 `;
 
-exports[`validate options should throw an error on the "appendData" option with "false" value 1`] = `
+exports[`validate options should throw an error on the "additionalData" option with "false" value 1`] = `
 "Invalid options object. Less Loader has been initialized using an options object that does not match the API schema.
- - options.appendData should be one of these:
+ - options.additionalData should be one of these:
    string | function
-   -> Add \`Less\` code after the actual entry file (https://github.com/webpack-contrib/less-loader#postponeddata).
+   -> Prepends/Appends \`Less\` code to the actual entry file (https://github.com/webpack-contrib/less-loader#additionalData).
    Details:
-    * options.appendData should be a string.
-    * options.appendData should be an instance of function."
+    * options.additionalData should be a string.
+    * options.additionalData should be an instance of function."
 `;
 
-exports[`validate options should throw an error on the "appendData" option with "true" value 1`] = `
+exports[`validate options should throw an error on the "additionalData" option with "true" value 1`] = `
 "Invalid options object. Less Loader has been initialized using an options object that does not match the API schema.
- - options.appendData should be one of these:
+ - options.additionalData should be one of these:
    string | function
-   -> Add \`Less\` code after the actual entry file (https://github.com/webpack-contrib/less-loader#postponeddata).
+   -> Prepends/Appends \`Less\` code to the actual entry file (https://github.com/webpack-contrib/less-loader#additionalData).
    Details:
-    * options.appendData should be a string.
-    * options.appendData should be an instance of function."
+    * options.additionalData should be a string.
+    * options.additionalData should be an instance of function."
 `;
 
 exports[`validate options should throw an error on the "implementation" option with "false" value 1`] = `
@@ -136,66 +136,6 @@ exports[`validate options should throw an error on the "lessOptions" option with
     * options.lessOptions should be an instance of function."
 `;
 
-exports[`validate options should throw an error on the "prependData" option with "/test/" value 1`] = `
-"Invalid options object. Less Loader has been initialized using an options object that does not match the API schema.
- - options.prependData should be one of these:
-   string | function
-   -> Prepends \`Less\` code before the actual entry file (https://github.com/webpack-contrib/less-loader#prependdata).
-   Details:
-    * options.prependData should be a string.
-    * options.prependData should be an instance of function."
-`;
-
-exports[`validate options should throw an error on the "prependData" option with "[]" value 1`] = `
-"Invalid options object. Less Loader has been initialized using an options object that does not match the API schema.
- - options.prependData should be one of these:
-   string | function
-   -> Prepends \`Less\` code before the actual entry file (https://github.com/webpack-contrib/less-loader#prependdata).
-   Details:
-    * options.prependData should be a string.
-    * options.prependData should be an instance of function."
-`;
-
-exports[`validate options should throw an error on the "prependData" option with "{}" value 1`] = `
-"Invalid options object. Less Loader has been initialized using an options object that does not match the API schema.
- - options.prependData should be one of these:
-   string | function
-   -> Prepends \`Less\` code before the actual entry file (https://github.com/webpack-contrib/less-loader#prependdata).
-   Details:
-    * options.prependData should be a string.
-    * options.prependData should be an instance of function."
-`;
-
-exports[`validate options should throw an error on the "prependData" option with "1" value 1`] = `
-"Invalid options object. Less Loader has been initialized using an options object that does not match the API schema.
- - options.prependData should be one of these:
-   string | function
-   -> Prepends \`Less\` code before the actual entry file (https://github.com/webpack-contrib/less-loader#prependdata).
-   Details:
-    * options.prependData should be a string.
-    * options.prependData should be an instance of function."
-`;
-
-exports[`validate options should throw an error on the "prependData" option with "false" value 1`] = `
-"Invalid options object. Less Loader has been initialized using an options object that does not match the API schema.
- - options.prependData should be one of these:
-   string | function
-   -> Prepends \`Less\` code before the actual entry file (https://github.com/webpack-contrib/less-loader#prependdata).
-   Details:
-    * options.prependData should be a string.
-    * options.prependData should be an instance of function."
-`;
-
-exports[`validate options should throw an error on the "prependData" option with "true" value 1`] = `
-"Invalid options object. Less Loader has been initialized using an options object that does not match the API schema.
- - options.prependData should be one of these:
-   string | function
-   -> Prepends \`Less\` code before the actual entry file (https://github.com/webpack-contrib/less-loader#prependdata).
-   Details:
-    * options.prependData should be a string.
-    * options.prependData should be an instance of function."
-`;
-
 exports[`validate options should throw an error on the "sourceMap" option with "string" value 1`] = `
 "Invalid options object. Less Loader has been initialized using an options object that does not match the API schema.
  - options.sourceMap should be a boolean.