SimenB · skimi · Mar 28, 2020
diff --git a/README.md b/README.md
@@ -58,7 +58,7 @@ look like:
 <!DOCTYPE html>
 <html>
   <head>
-    <meta charset="UTF-8">
+    <meta charset="UTF-8" />
     <title>Webpack App</title>
   </head>
   <body>
@@ -149,6 +149,19 @@ An example of this is included in the repository.
 
 Currently only supports script tags.
 
+### `inject`
+
+Type: `boolean | function`, default: `true`
+
+Inject conditionally.
+
+This option accepts arguments of different types:
+
+- boolean `false`: disables injection `true`: enables injection (defaults)
+- function any predicate that takes an instance of html-webpack-plugin and
+  returns either `true` or `false` to control the injection of html metadata for
+  the html files generated by this instance.
+
 ## Examples
 
 When adding assets, it's added to the start of the array, so when

diff --git a/src/index.js b/src/index.js
@@ -85,6 +85,7 @@ export default class AddAssetHtmlPlugin {
       publicPath,
       outputPath,
       files = [],
+      inject = true,
     },
   ) {
     if (!filepath) {
@@ -95,6 +96,15 @@ export default class AddAssetHtmlPlugin {
 
     const fileFilters = Array.isArray(files) ? files : [files];
 
+    const shouldInject =
+      typeof inject === 'function'
+        ? inject(htmlPluginData.plugin)
+        : Boolean(inject);
+
+    if (!shouldInject) {
+      return;
+    }
+
     if (fileFilters.length > 0) {
       const shouldSkip = !fileFilters.some(file =>
         micromatch.isMatch(htmlPluginData.outputName, file),

diff --git a/test.js b/test.js
@@ -286,3 +286,79 @@ test('filepath without globbyMagic should just return', async () => {
   const ret = await handleUrl(assets);
   expect(ret).toHaveLength(1);
 });
+
+describe('inject assets conditionally', () => {
+  test('does not inject if false', async () => {
+    const compilation = { options: { output: { publicPath: 'vendor/' } } };
+    const pluginData = Object.assign(
+      { assets: { js: [], css: [] } },
+      pluginMock,
+    );
+    const plugin = new AddAssetHtmlPlugin({
+      filepath: path.join(__dirname, 'my-file.js'),
+      inject: false,
+    });
+
+    await plugin.addAllAssetsToCompilation(compilation, pluginData);
+
+    expect(pluginData.assets.js).toHaveLength(0);
+  });
+
+  test('if inject is a callback it gets called with the HtmlPlugin data', async () => {
+    const mock = {
+      plugin: {
+        options: {
+          HTML_PLUGIN_OPTION: 'hello',
+        },
+      },
+    };
+
+    const compilation = { options: { output: { publicPath: 'vendor/' } } };
+    const pluginData = Object.assign({ assets: { js: [], css: [] } }, mock);
+    const injectCallback = jest.fn();
+    const plugin = new AddAssetHtmlPlugin({
+      filepath: path.join(__dirname, 'my-file.js'),
+      inject: injectCallback,
+    });
+
+    await plugin.addAllAssetsToCompilation(compilation, pluginData);
+
+    expect(injectCallback).toHaveBeenCalledWith(mock.plugin);
+  });
+
+  test('does not inject if the callback returns false', async () => {
+    const compilation = { options: { output: { publicPath: 'vendor/' } } };
+    const pluginData = Object.assign(
+      { assets: { js: [], css: [] } },
+      pluginMock,
+    );
+    const plugin = new AddAssetHtmlPlugin({
+      filepath: path.join(__dirname, 'my-file.js'),
+      inject: () => {
+        return false;
+      },
+    });
+
+    await plugin.addAllAssetsToCompilation(compilation, pluginData);
+
+    expect(pluginData.assets.js).toHaveLength(0);
+  });
+
+  test('injects if the callback returns true', async () => {
+    const compilation = { options: { output: { publicPath: 'vendor/' } } };
+    const pluginData = Object.assign(
+      { assets: { js: [], css: [] } },
+      pluginMock,
+    );
+    const plugin = new AddAssetHtmlPlugin({
+      filepath: path.join(__dirname, 'my-file.js'),
+      inject: () => {
+        return true;
+      },
+    });
+
+    await plugin.addAllAssetsToCompilation(compilation, pluginData);
+
+    expect(pluginData.assets.js).toHaveLength(1);
+  });
+});