1 files changed, 139 insertions, 0 deletions
diff --git a/packages/core/src/utils/paths.ts b/packages/core/src/utils/paths.ts
new file mode 100644
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+++ b/packages/core/src/utils/paths.ts
@@ -0,0 +1,139 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import path from 'node:path';
+import os from 'os';
+
+/**
+ * Replaces the home directory with a tilde.
+ * @param path - The path to tildeify.
+ * @returns The tildeified path.
+ */
+export function tildeifyPath(path: string): string {
+  const homeDir = os.homedir();
+  if (path.startsWith(homeDir)) {
+    return path.replace(homeDir, '~');
+  }
+  return path;
+}
+
+/**
+ * Shortens a path string if it exceeds maxLen, prioritizing the start and end segments.
+ * Example: /path/to/a/very/long/file.txt -> /path/.../long/file.txt
+ */
+export function shortenPath(filePath: string, maxLen: number = 35): string {
+  if (filePath.length <= maxLen) {
+    return filePath;
+  }
+
+  const parsedPath = path.parse(filePath);
+  const root = parsedPath.root;
+  const separator = path.sep;
+
+  // Get segments of the path *after* the root
+  const relativePath = filePath.substring(root.length);
+  const segments = relativePath.split(separator).filter((s) => s !== ''); // Filter out empty segments
+
+  // Handle cases with no segments after root (e.g., "/", "C:\") or only one segment
+  if (segments.length <= 1) {
+    // Fallback to simple start/end truncation for very short paths or single segments
+    const keepLen = Math.floor((maxLen - 3) / 2);
+    // Ensure keepLen is not negative if maxLen is very small
+    if (keepLen <= 0) {
+      return filePath.substring(0, maxLen - 3) + '...';
+    }
+    const start = filePath.substring(0, keepLen);
+    const end = filePath.substring(filePath.length - keepLen);
+    return `${start}...${end}`;
+  }
+
+  const firstDir = segments[0];
+  const startComponent = root + firstDir;
+
+  const endPartSegments: string[] = [];
+  // Base length: startComponent + separator + "..."
+  let currentLength = startComponent.length + separator.length + 3;
+
+  // Iterate backwards through segments (excluding the first one)
+  for (let i = segments.length - 1; i >= 1; i--) {
+    const segment = segments[i];
+    // Length needed if we add this segment: current + separator + segment
+    const lengthWithSegment = currentLength + separator.length + segment.length;
+
+    if (lengthWithSegment <= maxLen) {
+      endPartSegments.unshift(segment); // Add to the beginning of the end part
+      currentLength = lengthWithSegment;
+    } else {
+      // Adding this segment would exceed maxLen
+      break;
+    }
+  }
+
+  // Construct the final path
+  let result = startComponent + separator + '...';
+  if (endPartSegments.length > 0) {
+    result += separator + endPartSegments.join(separator);
+  }
+
+  // As a final check, if the result is somehow still too long (e.g., startComponent + ... is too long)
+  // fallback to simple truncation of the original path
+  if (result.length > maxLen) {
+    const keepLen = Math.floor((maxLen - 3) / 2);
+    if (keepLen <= 0) {
+      return filePath.substring(0, maxLen - 3) + '...';
+    }
+    const start = filePath.substring(0, keepLen);
+    const end = filePath.substring(filePath.length - keepLen);
+    return `${start}...${end}`;
+  }
+
+  return result;
+}
+
+/**
+ * Calculates the relative path from a root directory to a target path.
+ * Ensures both paths are resolved before calculating.
+ * Returns '.' if the target path is the same as the root directory.
+ *
+ * @param targetPath The absolute or relative path to make relative.
+ * @param rootDirectory The absolute path of the directory to make the target path relative to.
+ * @returns The relative path from rootDirectory to targetPath.
+ */
+export function makeRelative(
+  targetPath: string,
+  rootDirectory: string,
+): string {
+  const resolvedTargetPath = path.resolve(targetPath);
+  const resolvedRootDirectory = path.resolve(rootDirectory);
+
+  const relativePath = path.relative(resolvedRootDirectory, resolvedTargetPath);
+
+  // If the paths are the same, path.relative returns '', return '.' instead
+  return relativePath || '.';
+}
+
+/**
+ * Escapes spaces in a file path.
+ */
+export function escapePath(filePath: string): string {
+  let result = '';
+  for (let i = 0; i < filePath.length; i++) {
+    // Only escape spaces that are not already escaped.
+    if (filePath[i] === ' ' && (i === 0 || filePath[i - 1] !== '\\')) {
+      result += '\\ ';
+    } else {
+      result += filePath[i];
+    }
+  }
+  return result;
+}
+
+/**
+ * Unescapes spaces in a file path.
+ */
+export function unescapePath(filePath: string): string {
+  return filePath.replace(/\\ /g, ' ');
+}