init claude-code

utils/suggestions/shellHistoryCompletion.ts

@@ -0,0 +1,119 @@
+import { getHistory } from '../../history.js'
+import { logForDebugging } from '../debug.js'
+
+/**
+ * Result of shell history completion lookup
+ */
+export type ShellHistoryMatch = {
+  /** The full command from history */
+  fullCommand: string
+  /** The suffix to display as ghost text (the part after user's input) */
+  suffix: string
+}
+
+// Cache for shell history commands to avoid repeated async reads
+// History only changes when user submits a command, so a long TTL is fine
+let shellHistoryCache: string[] | null = null
+let shellHistoryCacheTimestamp = 0
+const CACHE_TTL_MS = 60000 // 60 seconds - history won't change while typing
+
+/**
+ * Get shell commands from history, with caching
+ */
+async function getShellHistoryCommands(): Promise<string[]> {
+  const now = Date.now()
+
+  // Return cached result if still fresh
+  if (shellHistoryCache && now - shellHistoryCacheTimestamp < CACHE_TTL_MS) {
+    return shellHistoryCache
+  }
+
+  const commands: string[] = []
+  const seen = new Set<string>()
+
+  try {
+    // Read history entries and filter for bash commands
+    for await (const entry of getHistory()) {
+      if (entry.display && entry.display.startsWith('!')) {
+        // Remove the '!' prefix to get the actual command
+        const command = entry.display.slice(1).trim()
+        if (command && !seen.has(command)) {
+          seen.add(command)
+          commands.push(command)
+        }
+      }
+      // Limit to 50 most recent unique commands
+      if (commands.length >= 50) {
+        break
+      }
+    }
+  } catch (error) {
+    logForDebugging(`Failed to read shell history: ${error}`)
+  }
+
+  shellHistoryCache = commands
+  shellHistoryCacheTimestamp = now
+  return commands
+}
+
+/**
+ * Clear the shell history cache (useful when history is updated)
+ */
+export function clearShellHistoryCache(): void {
+  shellHistoryCache = null
+  shellHistoryCacheTimestamp = 0
+}
+
+/**
+ * Add a command to the front of the shell history cache without
+ * flushing the entire cache.  If the command already exists in the
+ * cache it is moved to the front (deduped).  When the cache hasn't
+ * been populated yet this is a no-op – the next lookup will read
+ * the full history which already includes the new command.
+ */
+export function prependToShellHistoryCache(command: string): void {
+  if (!shellHistoryCache) {
+    return
+  }
+  const idx = shellHistoryCache.indexOf(command)
+  if (idx !== -1) {
+    shellHistoryCache.splice(idx, 1)
+  }
+  shellHistoryCache.unshift(command)
+}
+
+/**
+ * Find the best matching shell command from history for the given input
+ *
+ * @param input The current user input (without '!' prefix)
+ * @returns The best match, or null if no match found
+ */
+export async function getShellHistoryCompletion(
+  input: string,
+): Promise<ShellHistoryMatch | null> {
+  // Don't suggest for empty or very short input
+  if (!input || input.length < 2) {
+    return null
+  }
+
+  // Check the trimmed input to make sure there's actual content
+  const trimmedInput = input.trim()
+  if (!trimmedInput) {
+    return null
+  }
+
+  const commands = await getShellHistoryCommands()
+
+  // Find the first command that starts with the EXACT input (including spaces)
+  // This ensures "ls " matches "ls -lah" but "ls  " (2 spaces) does not
+  for (const command of commands) {
+    if (command.startsWith(input) && command !== input) {
+      return {
+        fullCommand: command,
+        suffix: command.slice(input.length),
+      }
+    }
+  }
+
+  return null
+}