13740927970

Committed 08 Mar 2025 07:51PM UTC coverage: 82.347% (-0.09%) from 82.436%

Build # 13740927970

Build Type

push

github

Committed by

pmcelhaney

Commit Message

rename interceptor to middleware

Run Details

1110 of 1241 branches covered (89.44%)

Branch coverage included in aggregate %.

14 of 17 new or added lines in 3 files covered. (82.35%)

9 existing lines in 1 file now uncovered.

3303 of 4118 relevant lines covered (80.21%)

63.1 hits per line

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82.5

/src/server/module-loader.ts

/* eslint-disable n/no-sync */
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");

interface ContextModule {
  Context?: Context;
  middleware?: MiddlewareFunction;
}

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

function isInterceptModule(
  module: ContextModule | Module,
): module is ContextModule & { middleware: MiddlewareFunction } {
  return "middleware" in module && typeof module.middleware === "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 = `/${parts.dir}/${parts.name}`
          .replaceAll("\\", "/")
          .replaceAll(/\/+/gu, "/");

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

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

    this.dependencyGraph.load(pathName);

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

      const endpoint = (await doImport(pathName)) as ContextModule | Module;

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

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

        this.contextRegistry.update(
          directory,

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

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

      if (
        basename(pathName).startsWith("_.middleware.") &&
        isInterceptModule(endpoint)
      ) {
        this.registry.addMiddleware(url, endpoint.middleware);
      }

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

pmcelhaney / counterfact / 13740927970

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