fix(action-fusion): then_run skipped for Git Bash/MSYS/Cygwin/WSL drive paths on Windows

docs/compatibility.md

@@ -19,6 +19,8 @@ The built-in edit/write definitions capture their working directory, so SoL-Pi c
 
 Action Fusion decodes `file://` targets with Node's `fileURLToPath()` before resolving the queue and hash-check path. This keeps file URLs, including percent-encoded filenames and Pi's optional `@` prefix, aligned with the file handled by the built-in mutation tool.
 
+On Windows it applies the same drive-path conversion Pi's own resolver applies, so Git Bash, MSYS, Cygwin, and WSL targets such as `/c/src/app.ts` and home-relative `~\` paths resolve to the file the built-in mutation tool wrote. On other platforms those inputs keep their POSIX meaning.
+
 The queue covers only fused operations registered by this SoL-Pi instance. External processes, direct built-in-tool calls outside the replacement, and unrelated extensions are not globally locked. SoL-Pi hashes the target immediately before launching `then_run` and skips the command if it observes an intervening content change.
 
 ## ObservationPack

src/sol-pi/extensions/action-fusion/file-queue.ts

@@ -9,17 +9,34 @@ import { basename, dirname, resolve } from "node:path";
 import { fileURLToPath } from "node:url";
 
 const queueTails = new Map<string, Promise<void>>();
+const WINDOWS_SHELL_DRIVE = /^\/(?:mnt\/|cygdrive\/)?([a-z])(?:\/(.*))?$/i;
 
 function stripToolPathPrefix(filePath: string): string {
 	return filePath.startsWith("@") ? filePath.slice(1) : filePath;
 }
 
+/**
+ * Git Bash, MSYS, Cygwin, and WSL hand Pi paths like `/c/src/app.ts`. On
+ * Windows, Pi's built-in mutation tools convert those to a native drive path
+ * before touching the filesystem, so the queue and hash guard must convert them
+ * the same way or they address a file the mutation never wrote.
+ */
+export function normalizeWindowsShellPath(filePath: string): string {
+	if (process.platform !== "win32") return filePath;
+	if (!filePath.startsWith("/") || filePath.startsWith("//") || filePath.includes("\\")) return filePath;
+	const match = WINDOWS_SHELL_DRIVE.exec(filePath);
+	if (!match?.[1]) return filePath;
+	return `${match[1].toUpperCase()}:\\${match[2]?.replaceAll("/", "\\") ?? ""}`;
+}
+
 export function resolveToolPath(cwd: string, filePath: string): string {
-	const stripped = stripToolPathPrefix(filePath);
+	const stripped = normalizeWindowsShellPath(stripToolPathPrefix(filePath));
 	// Pi accepts file URLs; the queue and hash guard must use the same target.
 	const expanded = stripped.startsWith("file://") ? fileURLToPath(stripped) : stripped;
 	if (expanded === "~") return homedir();
-	if (expanded.startsWith("~/")) return resolve(homedir(), expanded.slice(2));
+	if (expanded.startsWith("~/") || (process.platform === "win32" && expanded.startsWith("~\\"))) {
+		return resolve(homedir(), expanded.slice(2));
+	}
 	return resolve(cwd, expanded);
 }
 

tests/action-fusion-paths.test.ts

@@ -8,7 +8,8 @@ import { join, resolve } from "node:path";
 import { pathToFileURL } from "node:url";
 import type { ExtensionAPI, ExtensionContext, ToolDefinition } from "@earendil-works/pi-coding-agent";
 import { afterEach, describe, expect, it } from "vitest";
-import { resolveToolPath } from "../src/sol-pi/extensions/action-fusion/file-queue.ts";
+import { homedir } from "node:os";
+import { normalizeWindowsShellPath, resolveToolPath } from "../src/sol-pi/extensions/action-fusion/file-queue.ts";
 import { createActionFusionExtension, type ActionFusionOptions } from "../src/sol-pi/extensions/action-fusion/index.ts";
 
 const tempDirs: string[] = [];
@@ -29,6 +30,18 @@ function loadTools(options: ActionFusionOptions = {}): Map<string, ToolDefinitio
 	return tools;
 }
 
+/** Exercise the platform-dependent branches without a Windows runner. */
+function withPlatform(platform: NodeJS.Platform, run: () => void): void {
+	const original = Object.getOwnPropertyDescriptor(process, "platform");
+	if (!original) throw new Error("process.platform is not configurable");
+	Object.defineProperty(process, "platform", { ...original, value: platform });
+	try {
+		run();
+	} finally {
+		Object.defineProperty(process, "platform", original);
+	}
+}
+
 function context(cwd: string): ExtensionContext {
 	return {
 		cwd,
@@ -49,6 +62,36 @@ describe("Action Fusion file URL paths", () => {
 		expect(resolveToolPath(cwd, `@${url}`)).toBe(target);
 	});
 
+	it("converts Git Bash, MSYS, Cygwin, and WSL drive paths on Windows", () => {
+		withPlatform("win32", () => {
+			expect(normalizeWindowsShellPath("/c/src/app.ts")).toBe("C:\\src\\app.ts");
+			expect(normalizeWindowsShellPath("/mnt/d/work/notes.md")).toBe("D:\\work\\notes.md");
+			expect(normalizeWindowsShellPath("/cygdrive/e/x/y")).toBe("E:\\x\\y");
+			expect(normalizeWindowsShellPath("/c")).toBe("C:\\");
+			// Not a drive path: leave it alone.
+			expect(normalizeWindowsShellPath("/usr/local/bin/pi")).toBe("/usr/local/bin/pi");
+			expect(normalizeWindowsShellPath("//server/share/file.txt")).toBe("//server/share/file.txt");
+			expect(normalizeWindowsShellPath("C:\\already\\native.ts")).toBe("C:\\already\\native.ts");
+		});
+	});
+
+	it("leaves a POSIX path alone off Windows", () => {
+		withPlatform("linux", () => {
+			expect(normalizeWindowsShellPath("/c/src/app.ts")).toBe("/c/src/app.ts");
+			expect(resolveToolPath("/work", "/c/src/app.ts")).toBe("/c/src/app.ts");
+		});
+	});
+
+	it("expands a Windows home-relative path", () => {
+		withPlatform("win32", () => {
+			expect(resolveToolPath("/work", "~\\notes.txt")).toBe(resolve(homedir(), "notes.txt"));
+		});
+		withPlatform("linux", () => {
+			// A backslash is an ordinary filename character here.
+			expect(resolveToolPath("/work", "~\\notes.txt")).toBe(resolve("/work", "~\\notes.txt"));
+		});
+	});
+
 	it("preserves ordinary relative and absolute path semantics", () => {
 		const cwd = join(tmpdir(), "action-fusion-cwd");
 		const target = join(cwd, "target.txt");