fix: guard JSON.parse(result.stdout) with || "{}" fallback in hook handlers (#1191)

Co-authored-by: wangxiaoya.2000 <wangxiaoya.2000@bytedance.com>

src/hooks/claude-code-hooks/post-tool-use.ts

@@ -123,7 +123,7 @@ export async function executePostToolUseHooks(
 
         if (result.exitCode === 0 && result.stdout) {
           try {
-            const output = JSON.parse(result.stdout) as PostToolUseOutput
+            const output = JSON.parse(result.stdout || "{}") as PostToolUseOutput
             if (output.decision === "block") {
               return {
                 block: true,

src/hooks/claude-code-hooks/pre-compact.ts

@@ -73,7 +73,7 @@ export async function executePreCompactHooks(
 
       if (result.stdout) {
         try {
-          const output = JSON.parse(result.stdout) as PreCompactOutput
+          const output = JSON.parse(result.stdout || "{}") as PreCompactOutput
 
           if (output.hookSpecificOutput?.additionalContext) {
             collectedContext.push(...output.hookSpecificOutput.additionalContext)

src/hooks/claude-code-hooks/pre-tool-use.ts

@@ -117,7 +117,7 @@ export async function executePreToolUseHooks(
 
       if (result.stdout) {
         try {
-          const output = JSON.parse(result.stdout) as PreToolUseOutput
+          const output = JSON.parse(result.stdout || "{}") as PreToolUseOutput
 
           // Handle deprecated decision/reason fields (Claude Code backward compat)
           let decision: PermissionDecision | undefined

src/hooks/claude-code-hooks/stop.ts

@@ -93,7 +93,7 @@ export async function executeStopHooks(
 
        if (result.stdout) {
          try {
-           const output = JSON.parse(result.stdout) as StopOutput
+           const output = JSON.parse(result.stdout || "{}") as StopOutput
            if (output.stop_hook_active !== undefined) {
              stopHookActiveState.set(ctx.sessionId, output.stop_hook_active)
            }