add tests for the transform hooks

src/shims/fs/transforms.js

@@ -87,3 +87,10 @@ export function applyWriteTransform(path, data) {
     return data;
   }
 }
+
+// Test-only: clear all registered hooks.
+export function _reset() {
+  pathResolvers.length = 0;
+  readTransforms.clear();
+  writeTransforms.clear();
+}

src/shims/fs/transforms.test.js

@@ -0,0 +1,80 @@
+import { describe, it, expect, beforeEach } from "vitest";
+import {
+  registerPathResolver,
+  resolvePath,
+  registerReadTransform,
+  applyReadTransform,
+  registerWriteTransform,
+  applyWriteTransform,
+  _reset,
+} from "./transforms.js";
+
+beforeEach(() => {
+  _reset();
+});
+
+describe("resolvePath", () => {
+  it("returns the resolved path when a matcher hits", () => {
+    registerPathResolver(
+      (p) => p === ".obsidian/workspace.json",
+      () => ".obsidian/workspace.default.json",
+    );
+
+    expect(resolvePath(".obsidian/workspace.json")).toBe(
+      ".obsidian/workspace.default.json",
+    );
+  });
+
+  it("returns the input path when no matcher hits", () => {
+    registerPathResolver(
+      (p) => p === ".obsidian/workspace.json",
+      () => ".obsidian/workspace.default.json",
+    );
+
+    expect(resolvePath("notes/foo.md")).toBe("notes/foo.md");
+  });
+});
+
+describe("applyReadTransform", () => {
+  it("applies a registered transform when the path matches", () => {
+    registerReadTransform(".obsidian/core-plugins.json", (data) =>
+      data.replace('"sync":true', '"sync":false'),
+    );
+
+    const input = '{"sync":true,"foo":1}';
+    expect(applyReadTransform(".obsidian/core-plugins.json", input)).toBe(
+      '{"sync":false,"foo":1}',
+    );
+  });
+
+  it("returns data unchanged when no transform is registered for the path", () => {
+    registerReadTransform(".obsidian/core-plugins.json", (data) =>
+      data.replace('"sync":true', '"sync":false'),
+    );
+
+    const input = '{"sync":true}';
+    expect(applyReadTransform("notes/foo.md", input)).toBe(input);
+  });
+});
+
+describe("applyWriteTransform", () => {
+  it("applies a registered transform when the path matches", () => {
+    registerWriteTransform(".obsidian/workspaces.json", (data) =>
+      data.replace('"active":"w2"', '"active":"default"'),
+    );
+
+    const input = '{"active":"w2"}';
+    expect(applyWriteTransform(".obsidian/workspaces.json", input)).toBe(
+      '{"active":"default"}',
+    );
+  });
+});
+
+describe("path normalization", () => {
+  it("matches a path registered with one separator form against lookups in another", () => {
+    registerReadTransform(".obsidian/foo.json", (data) => `seen:${data}`);
+
+    expect(applyReadTransform(".obsidian\\foo.json", "x")).toBe("seen:x");
+    expect(applyReadTransform("/.obsidian/foo.json", "x")).toBe("seen:x");
+  });
+});