23924365346

Committed 02 Apr 2026 10:10PM UTC coverage: 85.966% (-0.1%) from 86.092%

Build # 23924365346

Build Type

push

github

Committed by

web-flow

Commit Message

Merge pull request #1614 from pmcelhaney/copilot/fix-counterfact-crash-on-file-delete

Fix crash when a route file is deleted

Coverage Stats

1632 of 1837 branches covered (88.84%)

Branch coverage included in aggregate %.

4 of 7 new or added lines in 1 file covered. (57.14%)

8 existing lines in 1 file now uncovered.

5039 of 5923 relevant lines covered (85.08%)

64.81 hits per line

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80.36

/src/server/module-loader.ts

import { once } from "node:events";
import { existsSync } from "node:fs";
import fs from "node:fs/promises";
import nodePath, { basename, dirname } from "node:path";

import { type FSWatcher, watch } from "chokidar";
import createDebug from "debug";

import { CHOKIDAR_OPTIONS } from "./constants.js";
import { type Context, ContextRegistry } from "./context-registry.js";
import { determineModuleKind } from "./determine-module-kind.js";
import { ModuleDependencyGraph } from "./module-dependency-graph.js";
import type { MiddlewareFunction, Module, Registry } from "./registry.js";
import { uncachedImport } from "./uncached-import.js";

const { uncachedRequire } = await import("./uncached-require.cjs");

const debug = createDebug("counterfact:server:module-loader");

import {
  escapePathForWindows,
  unescapePathForWindows,
} from "../util/windows-escape.js";

interface ContextModule {
  Context?: Context;
}

function isContextModule(
  module: ContextModule | Module,
): module is ContextModule {
  return "Context" in module && typeof module.Context === "function";
}

function isMiddlewareModule(
  module: ContextModule | Module,
): module is ContextModule & { middleware: MiddlewareFunction } {
  return (
    "middleware" in module &&
    typeof Object.getOwnPropertyDescriptor(module, "middleware")?.value ===
      "function"
  );
}

export class ModuleLoader extends EventTarget {
  private readonly basePath: string;

  public readonly registry: Registry;

  private watcher: FSWatcher | undefined;

  private readonly contextRegistry: ContextRegistry;

  private readonly dependencyGraph = new ModuleDependencyGraph();

  private readonly uncachedImport: (moduleName: string) => Promise<unknown> =
    async function (moduleName: string) {
      throw new Error(`uncachedImport not set up; importing ${moduleName}`);
    };

  public constructor(
    basePath: string,
    registry: Registry,
    contextRegistry = new ContextRegistry(),
  ) {
    super();
    this.basePath = basePath.replaceAll("\\", "/");
    this.registry = registry;
    this.contextRegistry = contextRegistry;
  }

  public async watch(): Promise<void> {
    this.watcher = watch(this.basePath, CHOKIDAR_OPTIONS).on(
      "all",

      (eventName: string, pathNameOriginal: string) => {
        const JS_EXTENSIONS = ["js", "mjs", "cjs", "ts", "mts", "cts"];

        if (
          !JS_EXTENSIONS.some((extension) =>
            pathNameOriginal.endsWith(`.${extension}`),
          )
        )
          return;

        const pathName = pathNameOriginal.replaceAll("\\", "/");

        if (pathName.includes("$.context") && eventName === "add") {
          process.stdout.write(
            `\n\n!!! The file at ${pathName} needs a minor update.\n    See https://github.com/pmcelhaney/counterfact/blob/main/docs/context-change.md\n\n\n`,
          );

          return;
        }

        if (!["add", "change", "unlink"].includes(eventName)) {
          return;
        }

        const parts = nodePath.parse(pathName.replace(this.basePath, ""));
        const url = unescapePathForWindows(
          `/${parts.dir}/${parts.name}`
            .replaceAll("\\", "/")
            .replaceAll(/\/+/gu, "/"),
        );

        if (eventName === "unlink") {
          this.registry.remove(url);
          this.dispatchEvent(new Event("remove"));
          return;
        }

        const dependencies = this.dependencyGraph.dependentsOf(pathName);

        void this.loadEndpoint(pathName);

        for (const dependency of dependencies) {
          void this.loadEndpoint(dependency);
        }
      },
    );
    await once(this.watcher, "ready");
  }

  public async stopWatching(): Promise<void> {
    await this.watcher?.close();
  }

  public async load(directory = ""): Promise<void> {
    if (
      !existsSync(nodePath.join(this.basePath, directory).replaceAll("\\", "/"))
    ) {
      throw new Error(`Directory does not exist ${this.basePath}`);
    }

    const files = await fs.readdir(
      nodePath.join(this.basePath, directory).replaceAll("\\", "/"),
      {
        withFileTypes: true,
      },
    );

    const imports = files.flatMap(async (file): Promise<void> => {
      const extension = file.name.split(".").at(-1);

      if (file.isDirectory()) {
        await this.load(
          nodePath.join(directory, file.name).replaceAll("\\", "/"),
        );

        return;
      }

      if (!["cjs", "cts", "js", "mjs", "mts", "ts"].includes(extension ?? "")) {
        return;
      }

      const fullPath = nodePath
        .join(this.basePath, directory, file.name)
        .replaceAll("\\", "/");

      await this.loadEndpoint(escapePathForWindows(fullPath));
    });

    await Promise.all(imports);
  }

  private async loadEndpoint(pathName: string) {
    debug("importing module: %s", pathName);

    const directory = dirname(pathName.slice(this.basePath.length)).replaceAll(
      "\\",
      "/",
    );

    const url = unescapePathForWindows(
      `/${nodePath.join(directory, nodePath.parse(basename(pathName)).name)}`
        .replaceAll("\\", "/")
        .replaceAll(/\/+/gu, "/"),
    );

    debug(`loading pathName from dependencyGraph: ${pathName}`);

    this.dependencyGraph.load(pathName);

    try {
      const doImport =
        (await determineModuleKind(pathName)) === "commonjs"
          ? uncachedRequire
          : uncachedImport;

      const endpoint = (await doImport(pathName).catch((error: unknown) => {
        console.error(`Failed to import ${pathName}:`, error);
      })) as ContextModule | Module;

      if (!endpoint) {
        return;
      }

      this.dispatchEvent(new Event("add"));

      if (
        basename(pathName).startsWith("_.context.") &&
        isContextModule(endpoint)
      ) {
        const loadContext = (path: string) => this.contextRegistry.find(path);

        const contextDir = nodePath.dirname(unescapePathForWindows(pathName));
        const readJson = async (relativePath: string): Promise<unknown> => {
          const absolutePath = nodePath.resolve(contextDir, relativePath);
          let content: string;
          try {
            content = await fs.readFile(absolutePath, "utf8");
          } catch {
            throw new Error(
              `readJson: could not read file at "${absolutePath}" (resolved from "${relativePath}" relative to "${contextDir}")`,
            );
          }
          try {
            return JSON.parse(content) as unknown;
          } catch {
            throw new Error(
              `readJson: file at "${absolutePath}" does not contain valid JSON`,
            );
          }
        };

        this.contextRegistry.update(
          directory,

          // @ts-expect-error TS says Context has no constructable signatures but that's not true?

          new endpoint.Context({
            loadContext,
            readJson,
          }),
        );
        return;
      }

      if (
        basename(pathName).startsWith("_.middleware.") &&
        isMiddlewareModule(endpoint)
      ) {
        this.registry.addMiddleware(
          url.slice(0, url.lastIndexOf("/")) || "/",
          endpoint.middleware,
        );
      }

      if (url === "/index") this.registry.add("/", endpoint as Module);

      debug(`adding "${url}" to registry`);
      this.registry.add(url, endpoint as Module);
    } catch (error: unknown) {
      if (
        String(error) ===
        "SyntaxError: Identifier 'Context' has already been declared"
      ) {
        // Not sure why Node throws this error. It doesn't seem to matter.
        return;
      }

      process.stdout.write(`\nError loading ${pathName}:\n${String(error)}\n`);

      throw error;
    }
  }
}

1	import { once } from "node:events";	2✔
2	import { existsSync } from "node:fs";	2✔
3	import fs from "node:fs/promises";	2✔
4	import nodePath, { basename, dirname } from "node:path";	2✔
5		2✔
6	import { type FSWatcher, watch } from "chokidar";	2✔
7	import createDebug from "debug";	2✔
8		2✔
9	import { CHOKIDAR_OPTIONS } from "./constants.js";	2✔
10	import { type Context, ContextRegistry } from "./context-registry.js";	2✔
11	import { determineModuleKind } from "./determine-module-kind.js";	2✔
12	import { ModuleDependencyGraph } from "./module-dependency-graph.js";	2✔
13	import type { MiddlewareFunction, Module, Registry } from "./registry.js";	2✔
14	import { uncachedImport } from "./uncached-import.js";	2✔
15		2✔
16	const { uncachedRequire } = await import("./uncached-require.cjs");	2✔
17		2✔
18	const debug = createDebug("counterfact:server:module-loader");	2✔
19		2✔
20	import {	2✔
21	escapePathForWindows,	2✔
22	unescapePathForWindows,	2✔
23	} from "../util/windows-escape.js";	2✔
24		2✔
25	interface ContextModule {	2✔
26	Context?: Context;	2✔
27	}	2✔
28		2✔
29	function isContextModule(	18✔
30	module: ContextModule \| Module,	18✔
31	): module is ContextModule {	18✔
32	return "Context" in module && typeof module.Context === "function";	18✔
33	}	18✔
34		2✔
35	function isMiddlewareModule(	4✔
36	module: ContextModule \| Module,	4✔
37	): module is ContextModule & { middleware: MiddlewareFunction } {	4✔
38	return (	4✔
39	"middleware" in module &&	4✔
40	typeof Object.getOwnPropertyDescriptor(module, "middleware")?.value ===	4✔
41	"function"	4✔
42	);	4✔
43	}	4✔
44		2✔
45	export class ModuleLoader extends EventTarget {	2✔
46	private readonly basePath: string;	2✔
47		28✔
48	public readonly registry: Registry;	28✔
49		28✔
50	private watcher: FSWatcher \| undefined;	28✔
51		28✔
52	private readonly contextRegistry: ContextRegistry;	28✔
53		28✔
54	private readonly dependencyGraph = new ModuleDependencyGraph();	28✔
55		28✔
56	private readonly uncachedImport: (moduleName: string) => Promise<unknown> =	28✔
57	async function (moduleName: string) {	28✔
58	throw new Error(`uncachedImport not set up; importing ${moduleName}`);	×
59	};	×
60		2✔
61	public constructor(	2✔
62	basePath: string,	28✔
63	registry: Registry,	28✔
64	contextRegistry = new ContextRegistry(),	28✔
65	) {	28✔
66	super();	28✔
67	this.basePath = basePath.replaceAll("\\", "/");	28✔
68	this.registry = registry;	28✔
69	this.contextRegistry = contextRegistry;	28✔
70	}	28✔
71		2✔
72	public async watch(): Promise<void> {	2✔
73	this.watcher = watch(this.basePath, CHOKIDAR_OPTIONS).on(	6✔
74	"all",	6✔
75		6✔
76	(eventName: string, pathNameOriginal: string) => {	6✔
77	const JS_EXTENSIONS = ["js", "mjs", "cjs", "ts", "mts", "cts"];	4✔
78		4✔
79	if (	4✔
80	!JS_EXTENSIONS.some((extension) =>	4✔
81	pathNameOriginal.endsWith(`.${extension}`),	4✔
82	)	4✔
83	)	4✔
84	return;	4!
85		4✔
86	const pathName = pathNameOriginal.replaceAll("\\", "/");	4✔
87		4✔
88	if (pathName.includes("$.context") && eventName === "add") {	4!
89	process.stdout.write(	×
90	`\n\n!!! The file at ${pathName} needs a minor update.\n See https://github.com/pmcelhaney/counterfact/blob/main/docs/context-change.md\n\n\n`,	×
91	);	×
92		×
93	return;	×
94	}	×
95		4✔
96	if (!["add", "change", "unlink"].includes(eventName)) {	4!
97	return;	×
98	}	×
99		4✔
100	const parts = nodePath.parse(pathName.replace(this.basePath, ""));	4✔
101	const url = unescapePathForWindows(	4✔
102	`/${parts.dir}/${parts.name}`	4✔
103	.replaceAll("\\", "/")	4✔
104	.replaceAll(/\/+/gu, "/"),	4✔
105	);	4✔
106		4✔
107	if (eventName === "unlink") {	4✔
108	this.registry.remove(url);	4✔
109	this.dispatchEvent(new Event("remove"));	4✔
110	return;	4✔
111	}	4!
UNCOV 112		×
UNCOV 113	const dependencies = this.dependencyGraph.dependentsOf(pathName);	×
UNCOV 114		×
UNCOV 115	void this.loadEndpoint(pathName);	×
UNCOV 116		×
UNCOV 117	for (const dependency of dependencies) {	×
118	void this.loadEndpoint(dependency);	×
119	}	×
UNCOV 120	},	×
121	);	6✔
122	await once(this.watcher, "ready");	6✔
123	}	6✔
124		2✔
125	public async stopWatching(): Promise<void> {	2✔
126	await this.watcher?.close();	8✔
127	}	8✔
128		2✔
129	public async load(directory = ""): Promise<void> {	2✔
130	if (	38✔
131	!existsSync(nodePath.join(this.basePath, directory).replaceAll("\\", "/"))	38✔
132	) {	38!
133	throw new Error(`Directory does not exist ${this.basePath}`);	×
134	}	×
135		38✔
136	const files = await fs.readdir(	38✔
137	nodePath.join(this.basePath, directory).replaceAll("\\", "/"),	38✔
138	{	38✔
139	withFileTypes: true,	38✔
140	},	38✔
141	);	38✔
142		38✔
143	const imports = files.flatMap(async (file): Promise<void> => {	38✔
144	const extension = file.name.split(".").at(-1);	78✔
145		78✔
146	if (file.isDirectory()) {	78✔
147	await this.load(	16✔
148	nodePath.join(directory, file.name).replaceAll("\\", "/"),	16✔
149	);	16✔
150		16✔
151	return;	16✔
152	}	16✔
153		62✔
154	if (!["cjs", "cts", "js", "mjs", "mts", "ts"].includes(extension ?? "")) {	78✔
155	return;	28✔
156	}	28✔
157		34✔
158	const fullPath = nodePath	34✔
159	.join(this.basePath, directory, file.name)	34✔
160	.replaceAll("\\", "/");	34✔
161		34✔
162	await this.loadEndpoint(escapePathForWindows(fullPath));	34✔
163	});	34✔
164		38✔
165	await Promise.all(imports);	38✔
166	}	38✔
167		2✔
168	private async loadEndpoint(pathName: string) {	2✔
169	debug("importing module: %s", pathName);	34✔
170		34✔
171	const directory = dirname(pathName.slice(this.basePath.length)).replaceAll(	34✔
172	"\\",	34✔
173	"/",	34✔
174	);	34✔
175		34✔
176	const url = unescapePathForWindows(	34✔
177	`/${nodePath.join(directory, nodePath.parse(basename(pathName)).name)}`	34✔
178	.replaceAll("\\", "/")	34✔
179	.replaceAll(/\/+/gu, "/"),	34✔
180	);	34✔
181		34✔
182	debug(`loading pathName from dependencyGraph: ${pathName}`);	34✔
183		34✔
184	this.dependencyGraph.load(pathName);	34✔
185		34✔
186	try {	34✔
187	const doImport =	34✔
188	(await determineModuleKind(pathName)) === "commonjs"	34!
189	? uncachedRequire	×
190	: uncachedImport;	34✔
191		34✔
192	const endpoint = (await doImport(pathName).catch((error: unknown) => {	34✔
NEW 193	console.error(`Failed to import ${pathName}:`, error);	×
UNCOV 194	})) as ContextModule \| Module;	×
195		34✔
196	if (!endpoint) {	34!
NEW 197	return;	×
NEW 198	}	×
199		34✔
200	this.dispatchEvent(new Event("add"));	34✔
201		34✔
202	if (	34✔
203	basename(pathName).startsWith("_.context.") &&	34✔
204	isContextModule(endpoint)	18✔
205	) {	34✔
206	const loadContext = (path: string) => this.contextRegistry.find(path);	18✔
207		18✔
208	const contextDir = nodePath.dirname(unescapePathForWindows(pathName));	18✔
209	const readJson = async (relativePath: string): Promise<unknown> => {	18✔
210	const absolutePath = nodePath.resolve(contextDir, relativePath);	4✔
211	let content: string;	4✔
212	try {	4✔
213	content = await fs.readFile(absolutePath, "utf8");	4✔
214	} catch {	4!
215	throw new Error(	×
216	`readJson: could not read file at "${absolutePath}" (resolved from "${relativePath}" relative to "${contextDir}")`,	×
217	);	×
218	}	×
219	try {	4✔
220	return JSON.parse(content) as unknown;	4✔
221	} catch {	4!
222	throw new Error(	×
223	`readJson: file at "${absolutePath}" does not contain valid JSON`,	×
224	);	×
225	}	×
226	};	4✔
227		18✔
228	this.contextRegistry.update(	18✔
229	directory,	18✔
230		18✔
231	// @ts-expect-error TS says Context has no constructable signatures but that's not true?	18✔
232		18✔
233	new endpoint.Context({	18✔
234	loadContext,	18✔
235	readJson,	18✔
236	}),	18✔
237	);	18✔
238	return;	18✔
239	}	18✔
240		16✔
241	if (	16✔
242	basename(pathName).startsWith("_.middleware.") &&	16✔
243	isMiddlewareModule(endpoint)	4✔
244	) {	34✔
245	this.registry.addMiddleware(	4✔
246	url.slice(0, url.lastIndexOf("/")) \|\| "/",	4✔
247	endpoint.middleware,	4✔
248	);	4✔
249	}	4✔
250		16✔
251	if (url === "/index") this.registry.add("/", endpoint as Module);	34✔
252		16✔
253	debug(`adding "${url}" to registry`);	16✔
254	this.registry.add(url, endpoint as Module);	16✔
255	} catch (error: unknown) {	34!
256	if (	×
257	String(error) ===	×
258	"SyntaxError: Identifier 'Context' has already been declared"	×
259	) {	×
260	// Not sure why Node throws this error. It doesn't seem to matter.	×
261	return;	×
262	}	×
263		×
264	process.stdout.write(`\nError loading ${pathName}:\n${String(error)}\n`);	×
265		×
266	throw error;	×
267	}	×
268	}	34✔
269	}	2✔

pmcelhaney / counterfact / 23924365346

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