feat(hooks): add comment-checker hook for detecting unnecessary comments

- Port Go comment-checker to TypeScript using web-tree-sitter
- Support 38 programming languages via tree-sitter-wasms
- Filter out valid comments: BDD patterns, lint directives, docstrings, shebangs
- Integrate with OpenCode's tool.execute.before/after hooks
- Attach feedback to Write/Edit/MultiEdit tool output

src/hooks/comment-checker/index.ts

@@ -0,0 +1,101 @@
+import type { PendingCall, FileComments } from "./types"
+import { detectComments, isSupportedFile } from "./detector"
+import { applyFilters } from "./filters"
+import { formatHookMessage } from "./output"
+
+const pendingCalls = new Map<string, PendingCall>()
+const PENDING_CALL_TTL = 60_000
+
+function cleanupOldPendingCalls(): void {
+  const now = Date.now()
+  for (const [callID, call] of pendingCalls) {
+    if (now - call.timestamp > PENDING_CALL_TTL) {
+      pendingCalls.delete(callID)
+    }
+  }
+}
+
+setInterval(cleanupOldPendingCalls, 10_000)
+
+export function createCommentCheckerHooks() {
+  return {
+    "tool.execute.before": async (
+      input: { tool: string; sessionID: string; callID: string },
+      output: { args: Record<string, unknown> }
+    ): Promise<void> => {
+      const toolLower = input.tool.toLowerCase()
+      if (toolLower !== "write" && toolLower !== "edit" && toolLower !== "multiedit") {
+        return
+      }
+
+      const filePath = (output.args.filePath ?? output.args.file_path) as string | undefined
+      const content = output.args.content as string | undefined
+
+      if (!filePath) {
+        return
+      }
+
+      if (!isSupportedFile(filePath)) {
+        return
+      }
+
+      pendingCalls.set(input.callID, {
+        filePath,
+        content,
+        tool: toolLower as "write" | "edit" | "multiedit",
+        sessionID: input.sessionID,
+        timestamp: Date.now(),
+      })
+    },
+
+    "tool.execute.after": async (
+      input: { tool: string; sessionID: string; callID: string },
+      output: { title: string; output: string; metadata: unknown }
+    ): Promise<void> => {
+      const pendingCall = pendingCalls.get(input.callID)
+      if (!pendingCall) {
+        return
+      }
+
+      pendingCalls.delete(input.callID)
+
+      if (output.output.toLowerCase().includes("error")) {
+        return
+      }
+
+      try {
+        let content: string
+
+        if (pendingCall.content) {
+          content = pendingCall.content
+        } else {
+          const file = Bun.file(pendingCall.filePath)
+          content = await file.text()
+        }
+
+        const rawComments = await detectComments(pendingCall.filePath, content)
+        const filteredComments = applyFilters(rawComments)
+
+        if (filteredComments.length === 0) {
+          return
+        }
+
+        const fileComments: FileComments[] = [
+          {
+            filePath: pendingCall.filePath,
+            comments: filteredComments,
+          },
+        ]
+
+        const message = formatHookMessage(fileComments)
+        output.output += `\n\n${message}`
+      } catch {}
+    },
+  }
+}
+
+export * from "./types"
+export * from "./constants"
+export * from "./detector"
+export * from "./filters"
+export * from "./output"