Add file system utils

Author: mayank1513

lib/src/utils.ts

@@ -0,0 +1,81 @@
+import fs from "node:fs/promises";
+import path from "node:path";
+import { NormalizedConfig } from "./normalizer";
+
+/**
+ * Checks whether the given file contains Git merge conflict markers.
+ *
+ * @param filePath - Absolute path to the file.
+ * @returns `true` if conflict markers exist, otherwise `false`.
+ */
+const hasConflict = async (filePath: string): Promise<boolean> => {
+  try {
+    const content = await fs.readFile(filePath, "utf8");
+    return (
+      content.includes("<<<<<<<") && content.includes("=======") && content.includes(">>>>>>>")
+    );
+  } catch {
+    // If file cannot be read (permissions, etc.), treat as non-conflicted
+    return false;
+  }
+};
+
+export interface CollectFilesOptions {
+  /** Root directory to start traversal (defaults to `process.cwd()`). */
+  root?: string;
+  /**
+   * Include files that match `fileFilter` even if they do not contain
+   * merge conflicts. Defaults to `false`.
+   */
+  includeNonConflicted?: boolean;
+}
+
+/**
+ * Recursively collects files that match the provided `fileFilter`.
+ *
+ * - By default, only conflicted files are returned.
+ * - If `includeNonConflicted` is enabled, matching files are always included
+ *   (skipping conflict check).
+ *
+ * @param config - Normalized configuration containing `fileFilter`.
+ * @param options - Behavior flags (e.g., `includeNonConflicted`).
+ * @returns A promise that resolves with an array of matching file paths.
+ */
+export const collectFiles = async (
+  config: NormalizedConfig,
+  options: CollectFilesOptions = {},
+): Promise<string[]> => {
+  const { root = process.cwd(), includeNonConflicted = false } = options;
+  const allFiles: string[] = [];
+
+  /**
+   * Recursively traverses a directory, checking each file against
+   * the filter and (if enabled) conflict conditions.
+   *
+   * @param dir - Directory path to walk through.
+   */
+  const walk = async (dir: string) => {
+    const entries = await fs.readdir(dir, { withFileTypes: true });
+
+    for (const entry of entries) {
+      const fullPath = path.join(dir, entry.name);
+
+      if (entry.isDirectory()) {
+        await walk(fullPath);
+      } else if (config.fileFilter(fullPath)) {
+        if (includeNonConflicted) {
+          allFiles.push(fullPath);
+        } else {
+          if (await hasConflict(fullPath)) {
+            allFiles.push(fullPath);
+          } else {
+            console.info(`Skipped (no conflicts): ${fullPath}`);
+          }
+        }
+      }
+    }
+  };
+
+  await walk(root);
+  return allFiles;
+};