fix(coding-agent): respect ignore files in skill loader

packages/coding-agent/src/core/skills.ts

@@ -1,6 +1,7 @@
 import { existsSync, readdirSync, readFileSync, realpathSync, statSync } from "fs";
+import ignore from "ignore";
 import { homedir } from "os";
-import { basename, dirname, isAbsolute, join, resolve, sep } from "path";
+import { basename, dirname, isAbsolute, join, relative, resolve, sep } from "path";
 import { CONFIG_DIR_NAME, getAgentDir } from "../config.js";
 import { parseFrontmatter } from "../utils/frontmatter.js";
 import type { ResourceDiagnostic } from "./diagnostics.js";
@@ -11,6 +12,57 @@ const MAX_NAME_LENGTH = 64;
 /** Max description length per spec */
 const MAX_DESCRIPTION_LENGTH = 1024;
 
+const IGNORE_FILE_NAMES = [".gitignore", ".ignore", ".fdignore"];
+
+type IgnoreMatcher = ReturnType<typeof ignore>;
+
+function toPosixPath(p: string): string {
+	return p.split(sep).join("/");
+}
+
+function prefixIgnorePattern(line: string, prefix: string): string | null {
+	const trimmed = line.trim();
+	if (!trimmed) return null;
+	if (trimmed.startsWith("#") && !trimmed.startsWith("\\#")) return null;
+
+	let pattern = line;
+	let negated = false;
+
+	if (pattern.startsWith("!")) {
+		negated = true;
+		pattern = pattern.slice(1);
+	} else if (pattern.startsWith("\\!")) {
+		pattern = pattern.slice(1);
+	}
+
+	if (pattern.startsWith("/")) {
+		pattern = pattern.slice(1);
+	}
+
+	const prefixed = prefix ? `${prefix}${pattern}` : pattern;
+	return negated ? `!${prefixed}` : prefixed;
+}
+
+function addIgnoreRules(ig: IgnoreMatcher, dir: string, rootDir: string): void {
+	const relativeDir = relative(rootDir, dir);
+	const prefix = relativeDir ? `${toPosixPath(relativeDir)}/` : "";
+
+	for (const filename of IGNORE_FILE_NAMES) {
+		const ignorePath = join(dir, filename);
+		if (!existsSync(ignorePath)) continue;
+		try {
+			const content = readFileSync(ignorePath, "utf-8");
+			const patterns = content
+				.split(/\r?\n/)
+				.map((line) => prefixIgnorePattern(line, prefix))
+				.filter((line): line is string => Boolean(line));
+			if (patterns.length > 0) {
+				ig.add(patterns);
+			}
+		} catch {}
+	}
+}
+
 export interface SkillFrontmatter {
 	name?: string;
 	description?: string;
@@ -96,7 +148,13 @@ export function loadSkillsFromDir(options: LoadSkillsFromDirOptions): LoadSkills
 	return loadSkillsFromDirInternal(dir, source, true);
 }
 
-function loadSkillsFromDirInternal(dir: string, source: string, includeRootFiles: boolean): LoadSkillsResult {
+function loadSkillsFromDirInternal(
+	dir: string,
+	source: string,
+	includeRootFiles: boolean,
+	ignoreMatcher?: IgnoreMatcher,
+	rootDir?: string,
+): LoadSkillsResult {
 	const skills: Skill[] = [];
 	const diagnostics: ResourceDiagnostic[] = [];
 
@@ -104,6 +162,10 @@ function loadSkillsFromDirInternal(dir: string, source: string, includeRootFiles
 		return { skills, diagnostics };
 	}
 
+	const root = rootDir ?? dir;
+	const ig = ignoreMatcher ?? ignore();
+	addIgnoreRules(ig, dir, root);
+
 	try {
 		const entries = readdirSync(dir, { withFileTypes: true });
 
@@ -133,8 +195,14 @@ function loadSkillsFromDirInternal(dir: string, source: string, includeRootFiles
 				}
 			}
 
+			const relPath = toPosixPath(relative(root, fullPath));
+			const ignorePath = isDirectory ? `${relPath}/` : relPath;
+			if (ig.ignores(ignorePath)) {
+				continue;
+			}
+
 			if (isDirectory) {
-				const subResult = loadSkillsFromDirInternal(fullPath, source, false);
+				const subResult = loadSkillsFromDirInternal(fullPath, source, false, ig, root);
 				skills.push(...subResult.skills);
 				diagnostics.push(...subResult.diagnostics);
 				continue;