feat: allow configuring identifiers in jest-transform plugin

.changeset/gorgeous-jars-hear.md

@@ -0,0 +1,22 @@
+---
+'@vanilla-extract/jest-transform': minor
+---
+
+Allow configuring [custom identifiers] in the jest transformer
+
+**EXAMPLE USAGE**:
+
+```js
+// jest.config.js
+
+export default {
+  transform: {
+    '^.+\\.css.ts$': [
+      '@vanilla-extract/jest-transform',
+      { identifiers: ({ hash }) => `${hash}_myCustomIdentifier` },
+    ],
+  },
+}
+```
+
+[custom identifiers]: https://vanilla-extract.style/documentation/integrations/webpack/#identifiers

packages/jest-transform/src/index.ts

@@ -4,39 +4,46 @@ import {
   transformSync,
   getPackageInfo,
   cssFileFilter,
+  IdentifierOption,
 } from '@vanilla-extract/integration';
 import * as esbuild from 'esbuild';
 
-const vanillaTransformer: Transformer = {
-  canInstrument: false,
-  process(source, filePath, options) {
-    if (!cssFileFilter.test(filePath)) {
-      // If the file that passes through to the transformer is not a VE file,
-      // then it's likely a vanilla .css file (because Jest can't differentiate
-      // between them)
-      return {
-        code: `module.exports = ${JSON.stringify(path.basename(filePath))};`,
-      };
-    }
+interface TransformerConfig {
+  identifiers: IdentifierOption;
+}
 
-    const { name: packageName } = getPackageInfo(options.config.rootDir);
+function createTransformer(config: TransformerConfig): Transformer {
+  const { identifiers = 'debug' } = config;
+  return {
+    canInstrument: false,
+    process(source, filePath, options) {
+      if (!cssFileFilter.test(filePath)) {
+        // If the file that passes through to the transformer is not a VE file,
+        // then it's likely a vanilla .css file (because Jest can't differentiate
+        // between them)
+        return {
+          code: `module.exports = ${JSON.stringify(path.basename(filePath))};`,
+        };
+      }
+      const { name: packageName } = getPackageInfo(options.config.rootDir);
 
-    const code = transformSync({
-      source,
-      filePath,
-      rootPath: options.config.rootDir,
-      packageName: packageName,
-      identOption: 'debug',
-    });
+      const code = transformSync({
+        source,
+        filePath,
+        rootPath: options.config.rootDir,
+        packageName: packageName,
+        identOption: identifiers,
+      });
 
-    const result = esbuild.transformSync(code, {
-      format: options.supportsStaticESM ? 'esm' : 'cjs',
-      target: 'es2018',
-      loader: 'ts',
-    });
+      const result = esbuild.transformSync(code, {
+        format: options.supportsStaticESM ? 'esm' : 'cjs',
+        target: 'es2018',
+        loader: 'ts',
+      });
 
-    return result;
-  },
-};
+      return result;
+    },
+  };
+}
 
-export default vanillaTransformer;
+export default { createTransformer };