fix: expose root in transform args now that it's gone on app.config

Author: marvinhagemeister

src/dev/builder.ts

@@ -7,7 +7,7 @@ import { bundleJs } from "./esbuild.ts";
 import { liveReload } from "./middlewares/live_reload.ts";
 import {
   cssAssetHash,
-  FreshFileTransformer,
+  FileTransformer,
   type OnTransformOptions,
 } from "./file_transformer.ts";
 import type { TransformFn } from "./file_transformer.ts";
@@ -93,7 +93,7 @@ const TEST_FILE_PATTERN = /[._]test\.(?:[tj]sx?|[mc][tj]s)$/;
 
 // deno-lint-ignore no-explicit-any
 export class Builder<State = any> {
-  #transformer = new FreshFileTransformer(fsAdapter);
+  #transformer: FileTransformer;
   #addedInternalTransforms = false;
   config: ResolvedBuildConfig;
   #islandSpecifiers = new Set<string>();
@@ -109,6 +109,8 @@ export class Builder<State = any> {
 
     this.#fsRoutes = { dir: routeDir, files: [], id: "default" };
 
+    this.#transformer = new FileTransformer(fsAdapter, root);
+
     this.config = {
       target: options?.target ?? ["chrome99", "firefox99", "safari15"],
       root,

src/dev/dev_build_cache_test.ts

@@ -1,6 +1,6 @@
 import { expect } from "@std/expect";
 import { MemoryBuildCache } from "./dev_build_cache.ts";
-import { FreshFileTransformer } from "./file_transformer.ts";
+import { FileTransformer } from "./file_transformer.ts";
 import { createFakeFs, withTmpDir } from "../test_utils.ts";
 import type { ResolvedBuildConfig } from "./builder.ts";
 
@@ -20,7 +20,7 @@ Deno.test({
       staticDir: "",
       target: "latest",
     };
-    const fileTransformer = new FreshFileTransformer(createFakeFs({}));
+    const fileTransformer = new FileTransformer(createFakeFs({}), tmp);
     const buildCache = new MemoryBuildCache(
       config,
       { dir: "", files: [], id: "" },

src/dev/file_transformer.ts

@@ -23,6 +23,7 @@ export interface OnTransformArgs {
   text: string;
   content: Uint8Array;
   mode: TransformMode;
+  root: string;
 }
 export type TransformFn = (
   args: OnTransformArgs,
@@ -56,21 +57,14 @@ interface TransformReq {
   inputFiles: string[];
 }
 
-export interface FileTransformer {
-  onTransform(options: OnTransformOptions, callback: TransformFn): void;
-  process(
-    filePath: string,
-    mode: TransformMode,
-    target: string | string[],
-  ): Promise<ProcessedFile[] | null>;
-}
-
-export class FreshFileTransformer implements FileTransformer {
+export class FileTransformer {
   #transformers: Transformer[] = [];
   #fs: FsAdapter;
+  #root: string;
 
-  constructor(fs: FsAdapter) {
+  constructor(fs: FsAdapter, root: string) {
     this.#fs = fs;
+    this.#root = root;
   }
 
   onTransform(options: OnTransformOptions, callback: TransformFn): void {
@@ -156,6 +150,7 @@ export class FreshFileTransformer implements FileTransformer {
           mode,
           target,
           content: req!.content,
+          root: this.#root,
           get text() {
             return new TextDecoder().decode(req!.content);
           },
@@ -252,7 +247,7 @@ export class FreshFileTransformer implements FileTransformer {
 
 const CSS_URL_REGEX = /url\(("[^"]+"|'[^']+'|[^)]+)\)/g;
 
-export function cssAssetHash(transformer: FreshFileTransformer) {
+export function cssAssetHash(transformer: FileTransformer) {
   transformer.onTransform({
     pluginName: "fresh-css",
     filter: /\.css$/,

src/dev/file_transformer_test.ts

@@ -1,14 +1,11 @@
 import { expect } from "@std/expect";
 import type { FsAdapter } from "../fs.ts";
-import {
-  FreshFileTransformer,
-  type ProcessedFile,
-} from "./file_transformer.ts";
+import { FileTransformer, type ProcessedFile } from "./file_transformer.ts";
 import { delay } from "../test_utils.ts";
 
-function testTransformer(files: Record<string, string>) {
+function testTransformer(files: Record<string, string>, root = "/") {
   const mockFs: FsAdapter = {
-    cwd: () => "/",
+    cwd: () => root,
     isDirectory: () => Promise.resolve(false),
     mkdirp: () => Promise.resolve(),
     walk: async function* foo() {
@@ -21,7 +18,7 @@ function testTransformer(files: Record<string, string>) {
       return Promise.resolve(buf);
     },
   };
-  return new FreshFileTransformer(mockFs);
+  return new FileTransformer(mockFs, root);
 }
 
 function consumeResult(result: ProcessedFile[]) {
@@ -228,3 +225,17 @@ Deno.test(
     ]);
   },
 );
+
+Deno.test("FileTransformer - pass root to args", async () => {
+  const transformer = testTransformer({ "foo.txt": "foo" }, "/<root>/");
+
+  let root = "";
+  transformer.onTransform({ pluginName: "A", filter: /.*/ }, (args) => {
+    root = args.root;
+    return undefined;
+  });
+
+  await transformer.process("foo.txt", "development", "");
+
+  expect(root).toEqual("/<root>/");
+});