init claude-code

utils/plugins/gitAvailability.ts

@@ -0,0 +1,69 @@
+/**
+ * Utility for checking git availability.
+ *
+ * Git is required for installing GitHub-based marketplaces. This module
+ * provides a memoized check to determine if git is available on the system.
+ */
+
+import memoize from 'lodash-es/memoize.js'
+import { which } from '../which.js'
+
+/**
+ * Check if a command is available in PATH.
+ *
+ * Uses which to find the actual executable without executing it.
+ * This is a security best practice to avoid executing arbitrary code
+ * in untrusted directories.
+ *
+ * @param command - The command to check for
+ * @returns True if the command exists and is executable
+ */
+async function isCommandAvailable(command: string): Promise<boolean> {
+  try {
+    return !!(await which(command))
+  } catch {
+    return false
+  }
+}
+
+/**
+ * Check if git is available on the system.
+ *
+ * This is memoized so repeated calls within a session return the cached result.
+ * Git availability is unlikely to change during a single CLI session.
+ *
+ * Only checks PATH — does not exec git. On macOS this means the /usr/bin/git
+ * xcrun shim passes even without Xcode CLT installed; callers that hit
+ * `xcrun: error:` at exec time should call markGitUnavailable() so the rest
+ * of the session behaves as though git is absent.
+ *
+ * @returns True if git is installed and executable
+ */
+export const checkGitAvailable = memoize(async (): Promise<boolean> => {
+  return isCommandAvailable('git')
+})
+
+/**
+ * Force the memoized git-availability check to return false for the rest of
+ * the session.
+ *
+ * Call this when a git invocation fails in a way that indicates the binary
+ * exists on PATH but cannot actually run — the macOS xcrun shim being the
+ * main case (`xcrun: error: invalid active developer path`). Subsequent
+ * checkGitAvailable() calls then short-circuit to false, so downstream code
+ * that guards on git availability skips cleanly instead of failing repeatedly
+ * with the same exec error.
+ *
+ * lodash memoize uses a no-arg cache key of undefined.
+ */
+export function markGitUnavailable(): void {
+  checkGitAvailable.cache?.set?.(undefined, Promise.resolve(false))
+}
+
+/**
+ * Clear the git availability cache.
+ * Used for testing purposes.
+ */
+export function clearGitAvailabilityCache(): void {
+  checkGitAvailable.cache?.clear?.()
+}