Feat: Allow dynamic config in @snowpack/plugin-postcss

FredKSchott · May 20, 2021 · 5a6c924 · 5a6c924
1 parent eae9121
commit 5a6c924
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Showing 3 changed files with 31 additions and 9 deletions.
diff --git a/plugins/plugin-postcss/plugin.js b/plugins/plugin-postcss/plugin.js
@@ -1,15 +1,18 @@
 'use strict';
 
-const {resolve, relative, isAbsolute} = require('path');
+const path = require('path');
 const workerpool = require('workerpool');
 
 module.exports = function postcssPlugin(snowpackConfig, options) {
   // options validation
   if (options) {
     if (typeof options !== 'object' || Array.isArray(options))
       throw new Error('options isn’t an object. Please see README.');
-    if (options.config && typeof options.config !== 'string')
-      throw new Error('options.config must be a path to a PostCSS config file.');
+    if (
+      (options.config && typeof options !== 'string' && typeof options !== 'object') ||
+      Array.isArray(options)
+    )
+      throw new Error('options.config must be a config object or a path to a PostCSS config file.');
   }
 
   let worker, pool;
@@ -23,8 +26,8 @@ module.exports = function postcssPlugin(snowpackConfig, options) {
 
       if (!input.includes(fileExt) || !contents) return;
 
-      if (config) {
-        config = resolve(config);
+      if (config && typeof config === 'string') {
+        config = path.resolve(config);
       }
 
       pool = pool || workerpool.pool(require.resolve('./worker.js'));
@@ -72,9 +75,9 @@ module.exports = function postcssPlugin(snowpackConfig, options) {
         }
         for (const dir of dirs) {
           // https://stackoverflow.com/a/45242825
-          const relativePath = relative(dir, filePath);
+          const relativePath = path.relative(dir, filePath);
           const dirContainsFilePath =
-            relativePath && !relativePath.startsWith('..') && !isAbsolute(relativePath);
+            relativePath && !relativePath.startsWith('..') && !path.isAbsolute(relativePath);
 
           if (dirContainsFilePath) {
             this.markChanged(id);

diff --git a/plugins/plugin-postcss/test/plugin.test.js b/plugins/plugin-postcss/test/plugin.test.js
@@ -70,4 +70,20 @@ describe('@snowpack/plugin-postcss', () => {
     expect(transformCSSResults).toBeFalsy();
     await pluginInstance.cleanup();
   });
+
+  test('allows dynamic config', async () => {
+    const pluginInstance = plugin(
+      {root: path.resolve(__dirname, 'stubs')},
+      {config: {plugins: {cssnano: {}}}},
+    );
+    const transformCSSResults = await pluginInstance.transform({
+      id: cssPath,
+      fileExt: path.extname(cssPath),
+      contents: cssContent,
+    });
+    expect(transformCSSResults.code).toBe(minCssContent); // TODO: remove this?
+    expect(transformCSSResults.contents).toBe(minCssContent);
+    expect(transformCSSResults.map).toBe(undefined);
+    await pluginInstance.cleanup();
+  });
 });
diff --git a/plugins/plugin-postcss/worker.js b/plugins/plugin-postcss/worker.js
@@ -9,9 +9,12 @@ let process = null;
 async function transformAsync(css, {filepath, config, cwd, map}) {
   // Initialize processor. `config`, `cwd` won't change until Snowpack is restarted
   if (!process) {
-    const {plugins, rcOptions} = await postcssrc({}, config || cwd);
+    const {plugins, options} =
+      typeof config === 'string'
+        ? await postcssrc({}, config || cwd)
+        : await postcssrc(config, cwd);
     const processor = postcss(plugins);
-    process = (css) => processor.process(css, {...rcOptions, from: filepath, map});
+    process = (css) => processor.process(css, {...options, from: filepath, map});
   }
 
   const result = await process(css);