refactor: selective catches in write-commands, cdp-inspector, meta-commands, snapshot

Convert ~27 empty/obscuring catches to selective error handling across 4
browse source files. CDP ops check for closed/Target/detached messages,
DOM ops check TypeError/DOMException, filesystem ops check ENOENT/EACCES,
JSON parsing checks SyntaxError. Remove dead code in cdp-inspector where
try/catch wrapped synchronous no-ops.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

browse/src/cdp-inspector.ts

@@ -98,8 +98,9 @@ async function getOrCreateSession(page: Page): Promise<any> {
     try {
       await session.send('DOM.getDocument', { depth: 0 });
       return session;
-    } catch {
-      // Session is stale — recreate
+    } catch (err: any) {
+      // Session is stale — recreate (CDP disconnects throw on closed/Target errors)
+      if (!err?.message?.includes('closed') && !err?.message?.includes('Target') && !err?.message?.includes('detached')) throw err;
       cdpSessions.delete(page);
       initializedPages.delete(page);
     }
@@ -117,7 +118,9 @@ async function getOrCreateSession(page: Page): Promise<any> {
   page.once('framenavigated', () => {
     try {
       session.detach().catch(() => {});
-    } catch {}
+    } catch (err: any) {
+      if (!err?.message?.includes('closed') && !err?.message?.includes('Target') && !err?.message?.includes('detached')) throw err;
+    }
     cdpSessions.delete(page);
     initializedPages.delete(page);
   });
@@ -258,8 +261,9 @@ export async function inspectElement(
         left: border[0] - margin[0],
       },
     };
-  } catch {
-    // Element may not have a box model (e.g., display:none)
+  } catch (err: any) {
+    // Element may not have a box model (e.g., display:none) — CDP returns "Could not compute box model"
+    if (!err?.message?.includes('box model') && !err?.message?.includes('Could not compute')) throw err;
   }
 
   // Get matched styles
@@ -315,10 +319,8 @@ export async function inspectElement(
 
       if (rule.styleSheetId) {
         styleSheetId = rule.styleSheetId;
-        try {
-          // Try to resolve stylesheet URL
-          source = rule.origin === 'regular' ? (rule.styleSheetId || 'stylesheet') : rule.origin;
-        } catch {}
+        // Resolve stylesheet source name
+        source = rule.origin === 'regular' ? (rule.styleSheetId || 'stylesheet') : rule.origin;
       }
 
       if (rule.style?.range) {
@@ -328,15 +330,7 @@ export async function inspectElement(
       }
 
       // Try to get a friendly source name from stylesheet
-      if (styleSheetId) {
-        try {
-          // Stylesheet URL might be embedded in the rule data
-          // CDP provides sourceURL in some cases
-          if (rule.style?.cssText) {
-            // Parse source from the styleSheetId metadata
-          }
-        } catch {}
-      }
+      // (styleSheetId metadata is available via CDP — see stylesheet URL resolution below)
 
       // Get media query if present
       let media: string | undefined;
@@ -433,15 +427,9 @@ export async function inspectElement(
   }
 
   // Resolve stylesheet URLs for better source info
-  for (const rule of matchedRules) {
-    if (rule.styleSheetId && rule.source !== 'inline') {
-      try {
-        const sheetMeta = await session.send('CSS.getStyleSheetText', { styleSheetId: rule.styleSheetId }).catch(() => null);
-        // Try to get the stylesheet header for URL info
-        // The styleSheetId itself is opaque, but we can try to get source URL
-      } catch {}
-    }
-  }
+  // Note: CSS.getStyleSheetText is called per-rule but result is unused — the styleSheetId
+  // is opaque and CDP doesn't expose a direct URL lookup. Left as a placeholder for future
+  // enhancement (e.g., CSS.styleSheetAdded event tracking).
 
   return {
     selector,
@@ -531,8 +519,9 @@ export async function modifyStyle(
         method = 'setStyleTexts';
         source = `${targetRule.source}:${targetRule.sourceLine}`;
         sourceLine = targetRule.sourceLine;
-      } catch {
-        // Fall back to inline
+      } catch (err: any) {
+        // Fall back to inline — setStyleTexts fails on immutable stylesheets or stale ranges
+        if (!err?.message?.includes('style') && !err?.message?.includes('range') && !err?.message?.includes('closed') && !err?.message?.includes('Target')) throw err;
       }
     }
 
@@ -591,8 +580,9 @@ export async function undoModification(page: Page, index?: number): Promise<void
       await modifyStyle(page, mod.selector, mod.property, mod.oldValue);
       // Remove the undo modification from history (it's a restore, not a new mod)
       modificationHistory.pop();
-    } catch {
-      // Fall back to inline restore
+    } catch (err: any) {
+      // Fall back to inline restore — CDP may have disconnected or stylesheet changed
+      if (!err?.message?.includes('closed') && !err?.message?.includes('Target') && !err?.message?.includes('style') && !err?.message?.includes('not found') && !err?.message?.includes('Element')) throw err;
       await page.evaluate(
         ([sel, prop, val]) => {
           const el = document.querySelector(sel);
@@ -652,8 +642,9 @@ export async function resetModifications(page: Page): Promise<void> {
         },
         [mod.selector, mod.property, mod.oldValue]
       );
-    } catch {
-      // Best effort
+    } catch (err: any) {
+      // Best effort — page may have navigated or element may be gone
+      if (!err?.message?.includes('closed') && !err?.message?.includes('Target') && !err?.message?.includes('Execution context')) throw err;
     }
   }
   modificationHistory.length = 0;
@@ -757,7 +748,7 @@ export function detachSession(page?: Page): void {
   if (page) {
     const session = cdpSessions.get(page);
     if (session) {
-      try { session.detach().catch(() => {}); } catch {}
+      try { session.detach().catch(() => {}); } catch (err: any) { if (!err?.message?.includes('closed') && !err?.message?.includes('Target') && !err?.message?.includes('detached')) throw err; }
       cdpSessions.delete(page);
       initializedPages.delete(page);
     }

browse/src/meta-commands.ts

@@ -248,8 +248,9 @@ export async function handleMetaCommand(
       try {
         commands = JSON.parse(jsonStr);
         if (!Array.isArray(commands)) throw new Error('not array');
-      } catch {
+      } catch (err: any) {
         // Fallback: pipe-delimited format "goto url | click @e5 | snapshot -ic"
+        if (!(err instanceof SyntaxError) && err?.message !== 'not array') throw err;
         commands = jsonStr.split(' | ')
           .filter(seg => seg.trim().length > 0)
           .map(seg => tokenizePipeSegment(seg.trim()));
@@ -291,7 +292,7 @@ export async function handleMetaCommand(
           } else {
             // Parse error from JSON result
             let errMsg = cr.result;
-            try { errMsg = JSON.parse(cr.result).error || cr.result; } catch {}
+            try { errMsg = JSON.parse(cr.result).error || cr.result; } catch (err: any) { if (!(err instanceof SyntaxError)) throw err; }
             results.push(`[${name}] ERROR: ${errMsg}`);
           }
           lastWasWrite = WRITE_COMMANDS.has(name);
@@ -431,8 +432,9 @@ export async function handleMetaCommand(
             execSync(`osascript -e 'tell application "${appName}" to activate'`, { stdio: 'pipe', timeout: 3000 });
             activated = true;
             break;
-          } catch {
-            // Try next browser
+          } catch (err: any) {
+            // Try next browser — osascript fails if app not found or AppleScript errors
+            if (err?.status === undefined && !err?.message?.includes('Command failed')) throw err;
           }
         }
 
@@ -448,8 +450,9 @@ export async function handleMetaCommand(
               await resolved.locator.scrollIntoViewIfNeeded({ timeout: 5000 });
               return `Browser activated. Scrolled ${args[0]} into view.`;
             }
-          } catch {
-            // Ref not found — still activated the browser
+          } catch (err: any) {
+            // Ref not found or element gone — still activated the browser
+            if (!err?.message?.includes('not found') && !err?.message?.includes('closed') && !err?.message?.includes('Target') && !err?.message?.includes('timeout')) throw err;
           }
         }
 
@@ -491,7 +494,9 @@ export async function handleMetaCommand(
       let gitRoot: string;
       try {
         gitRoot = execSync('git rev-parse --show-toplevel', { encoding: 'utf-8', stdio: ['pipe', 'pipe', 'pipe'] }).trim();
-      } catch {
+      } catch (err: any) {
+        // execSync throws with exit status on non-git directories
+        if (err?.status === undefined && !err?.message?.includes('Command failed')) throw err;
         return 'Not in a git repository — cannot locate inbox.';
       }
 
@@ -514,8 +519,9 @@ export async function handleMetaCommand(
             url: data.page?.url || 'unknown',
             userMessage: data.userMessage || '',
           });
-        } catch {
-          // Skip malformed files
+        } catch (err: any) {
+          // Skip malformed JSON or unreadable files
+          if (!(err instanceof SyntaxError) && err?.code !== 'ENOENT' && err?.code !== 'EACCES') throw err;
         }
       }
 
@@ -537,7 +543,7 @@ export async function handleMetaCommand(
       // Handle --clear flag
       if (args.includes('--clear')) {
         for (const file of files) {
-          try { fs.unlinkSync(path.join(inboxDir, file)); } catch {}
+          try { fs.unlinkSync(path.join(inboxDir, file)); } catch (err: any) { if (err?.code !== 'ENOENT') throw err; }
         }
         lines.push(`Cleared ${files.length} message${files.length === 1 ? '' : 's'}.`);
       }

browse/src/snapshot.ts

@@ -331,7 +331,9 @@ export async function handleSnapshot(
           output.push(`@${ref} [${elem.reason}] "${elem.text}"`);
         }
       }
-    } catch {
+    } catch (err: any) {
+      // Cursor scan fails on pages with strict CSP or when page has navigated
+      if (!err?.message?.includes('Execution context') && !err?.message?.includes('closed') && !err?.message?.includes('Target') && !err?.message?.includes('Content Security')) throw err;
       output.push('');
       output.push('(cursor scan failed — CSP restriction)');
     }
@@ -355,7 +357,7 @@ export async function handleSnapshot(
       const nodeFs = require('fs') as typeof import('fs');
       const absolute = nodePath.resolve(screenshotPath);
       const safeDirs = [TEMP_DIR, process.cwd()].map((d: string) => {
-        try { return nodeFs.realpathSync(d); } catch { return d; }
+        try { return nodeFs.realpathSync(d); } catch (err: any) { if (err?.code !== 'ENOENT') throw err; return d; }
       });
       let realPath: string;
       try {
@@ -365,7 +367,8 @@ export async function handleSnapshot(
           try {
             const dir = nodeFs.realpathSync(nodePath.dirname(absolute));
             realPath = nodePath.join(dir, nodePath.basename(absolute));
-          } catch {
+          } catch (err2: any) {
+            if (err2?.code !== 'ENOENT') throw err2;
             realPath = absolute;
           }
         } else {
@@ -385,8 +388,9 @@ export async function handleSnapshot(
           if (box) {
             boxes.push({ ref: `@${ref}`, box });
           }
-        } catch {
-          // Element may be offscreen or hidden — skip
+        } catch (err: any) {
+          // Element may be offscreen, hidden, or page navigated — skip
+          if (!err?.message?.includes('Timeout') && !err?.message?.includes('timeout') && !err?.message?.includes('closed') && !err?.message?.includes('Target') && !err?.message?.includes('Execution context')) throw err;
         }
       }
 
@@ -418,13 +422,16 @@ export async function handleSnapshot(
 
       output.push('');
       output.push(`[annotated screenshot: ${screenshotPath}]`);
-    } catch {
-      // Remove overlays even on screenshot failure
+    } catch (err: any) {
+      // Remove overlays even on screenshot failure — but only swallow page/browser errors
+      if (!err?.message?.includes('closed') && !err?.message?.includes('Target') && !err?.message?.includes('Execution context') && !err?.message?.includes('screenshot')) throw err;
       try {
         await page.evaluate(() => {
           document.querySelectorAll('.__browse_annotation__').forEach(el => el.remove());
         });
-      } catch {}
+      } catch (err2: any) {
+        if (!err2?.message?.includes('closed') && !err2?.message?.includes('Target') && !err2?.message?.includes('Execution context')) throw err2;
+      }
     }
   }
 

browse/src/write-commands.ts

@@ -399,7 +399,7 @@ export async function handleWriteCommand(
         if (!fs.existsSync(fp)) throw new Error(`File not found: ${fp}`);
         if (path.isAbsolute(fp)) {
           let resolvedFp: string;
-          try { resolvedFp = fs.realpathSync(path.resolve(fp)); } catch { resolvedFp = path.resolve(fp); }
+          try { resolvedFp = fs.realpathSync(path.resolve(fp)); } catch (err: any) { if (err?.code !== 'ENOENT') throw err; resolvedFp = path.resolve(fp); }
           if (!SAFE_DIRECTORIES.some(dir => isPathWithin(resolvedFp, dir))) {
             throw new Error(`Path must be within: ${SAFE_DIRECTORIES.join(', ')}`);
           }
@@ -455,7 +455,7 @@ export async function handleWriteCommand(
       if (!fs.existsSync(filePath)) throw new Error(`File not found: ${filePath}`);
       const raw = fs.readFileSync(filePath, 'utf-8');
       let cookies: any[];
-      try { cookies = JSON.parse(raw); } catch { throw new Error(`Invalid JSON in ${filePath}`); }
+      try { cookies = JSON.parse(raw); } catch (err: any) { throw new Error(`Invalid JSON in ${filePath}: ${err?.message || err}`); }
       if (!Array.isArray(cookies)) throw new Error('Cookie file must contain a JSON array');
 
       // Auto-fill domain from current page URL when missing (consistent with cookie command)
@@ -520,8 +520,9 @@ export async function handleWriteCommand(
       const pickerUrl = `http://127.0.0.1:${port}/cookie-picker?code=${code}`;
       try {
         Bun.spawn(['open', pickerUrl], { stdout: 'ignore', stderr: 'ignore' });
-      } catch {
-        // open may fail silently — URL is in the message below
+      } catch (err: any) {
+        // open may fail on non-macOS or if 'open' binary is missing — URL is in the message below
+        if (err?.code !== 'ENOENT' && !err?.message?.includes('spawn')) throw err;
       }
 
       return `Cookie picker opened at http://127.0.0.1:${port}/cookie-picker\nDetected browsers: ${browsers.map(b => b.name).join(', ')}\nSelect domains to import, then close the picker when done.`;
@@ -606,7 +607,10 @@ export async function handleWriteCommand(
                 (el as HTMLElement).style.setProperty('display', 'none', 'important');
                 removed++;
               });
-            } catch {}
+            } catch (err: any) {
+              // querySelectorAll throws DOMException on invalid CSS selectors — skip those
+              if (!(err instanceof DOMException)) throw err;
+            }
           }
           return removed;
         }, selectors);
@@ -815,7 +819,9 @@ export async function handleWriteCommand(
               document.querySelectorAll(sel).forEach(el => {
                 (el as HTMLElement).style.display = 'none';
               });
-            } catch {}
+            } catch (err: any) {
+              if (!(err instanceof DOMException)) throw err;
+            }
           }
           // Also hide fixed/sticky (except nav)
           for (const el of document.querySelectorAll('*')) {
@@ -838,7 +844,9 @@ export async function handleWriteCommand(
               document.querySelectorAll(sel).forEach(el => {
                 (el as HTMLElement).style.display = 'none';
               });
-            } catch {}
+            } catch (err: any) {
+              if (!(err instanceof DOMException)) throw err;
+            }
           }
         }, hideSelectors);
       }
@@ -950,13 +958,13 @@ export async function handleWriteCommand(
               reader.onerror = () => reject('Failed to read blob');
               reader.readAsDataURL(blob);
             });
-          } catch {
-            return 'ERROR:EXPIRED';
+          } catch (err: any) {
+            return `ERROR:EXPIRED:${err?.message || 'unknown'}`;
           }
         }, url);
 
         if (dataUrl === 'ERROR:TOO_LARGE') throw new Error('Blob too large (>100MB). Use a different approach.');
-        if (dataUrl === 'ERROR:EXPIRED') throw new Error('Blob URL expired or inaccessible.');
+        if (dataUrl.startsWith('ERROR:EXPIRED')) throw new Error(`Blob URL expired or inaccessible: ${dataUrl.slice('ERROR:EXPIRED:'.length)}`);
 
         const match = dataUrl.match(/^data:([^;]+);base64,(.+)$/);
         if (!match) throw new Error('Failed to decode blob data');