fix(cli): import plugin artifacts through file URLs

.changeset/calm-validator-paths.md

@@ -0,0 +1,5 @@
+---
+"emdash": patch
+---
+
+Fixes `emdash plugin bundle` and `emdash plugin validate` on Windows by importing generated plugin artifacts through portable file URLs.

packages/core/src/cli/commands/bundle-utils.ts

@@ -9,6 +9,7 @@ import { createWriteStream } from "node:fs";
 import { readdir, stat, access } from "node:fs/promises";
 import { resolve, join } from "node:path";
 import { pipeline } from "node:stream/promises";
+import { pathToFileURL } from "node:url";
 
 import { imageSize } from "image-size";
 import { packTar } from "modern-tar/fs";
@@ -105,6 +106,11 @@ export async function fileExists(path: string): Promise<boolean> {
 	}
 }
 
+/** Convert an absolute build artifact path into a portable ESM import specifier. */
+export function toFileImportSpecifier(path: string): string {
+	return pathToFileURL(path).href;
+}
+
 // ── Image dimension readers ──────────────────────────────────────────────────
 
 /**

packages/core/src/cli/commands/bundle.ts

@@ -37,6 +37,7 @@ import {
 	MAX_SCREENSHOT_HEIGHT,
 	readImageDimensions,
 	resolveSourceEntry,
+	toFileImportSpecifier,
 	totalBundleBytes,
 	validateBundleSize,
 } from "./bundle-utils.js";
@@ -202,7 +203,10 @@ export const bundleCommand = defineCommand({
 			}
 
 			// Dynamic import of the built plugin
-			const pluginModule = (await import(mainOutputPath)) as Record<string, unknown>;
+			const pluginModule = (await import(toFileImportSpecifier(mainOutputPath))) as Record<
+				string,
+				unknown
+			>;
 
 			// Extract manifest from the imported module.
 			// Supports three patterns:
@@ -269,7 +273,9 @@ export const bundleCommand = defineCommand({
 								const backendBaseName = basename(backendEntry).replace(TS_EXT_RE, "");
 								const backendProbePath = await findBuildOutput(backendProbeDir, backendBaseName);
 								if (backendProbePath) {
-									const backendModule = (await import(backendProbePath)) as Record<string, unknown>;
+									const backendModule = (await import(
+										toFileImportSpecifier(backendProbePath)
+									)) as Record<string, unknown>;
 									const standardDef = (backendModule.default ?? {}) as Record<string, unknown>;
 									const hooks = standardDef.hooks as Record<string, unknown> | undefined;
 									const routes = standardDef.routes as Record<string, unknown> | undefined;

packages/core/tests/unit/cli/bundle-utils.test.ts

@@ -22,6 +22,7 @@ import {
 	findNodeBuiltinImports,
 	findBuildOutput,
 	findSourceExports,
+	toFileImportSpecifier,
 } from "../../../src/cli/commands/bundle-utils.js";
 import type { ResolvedPlugin } from "../../../src/plugins/types.js";
 
@@ -277,6 +278,16 @@ describe("findBuildOutput", () => {
 	});
 });
 
+describe("toFileImportSpecifier", () => {
+	it("returns a file URL for an absolute build artifact path", () => {
+		const artifactPath = join(tmpdir(), "emdash-plugin", "index.mjs");
+		const specifier = toFileImportSpecifier(artifactPath);
+
+		expect(new URL(specifier).protocol).toBe("file:");
+		expect(specifier).not.toBe(artifactPath);
+	});
+});
+
 describe("findNodeBuiltinImports", () => {
 	it("detects require('node:fs') in bundled output", () => {
 		expect(findNodeBuiltinImports(`const fs = require("node:fs");`)).toEqual(["fs"]);