Remove unused catch vars

Author: jakebailey

eslint.config.mjs

@@ -131,6 +131,7 @@ export default tseslint.config(
                     // Ignore: (solely underscores | starting with exactly one underscore)
                     argsIgnorePattern: "^(_+$|_[^_])",
                     varsIgnorePattern: "^(_+$|_[^_])",
+                    // Not setting an ignore pattern for caught errors; those can always be safely removed.
                 },
             ],
             "@typescript-eslint/no-inferrable-types": "off",

scripts/failed-tests.cjs

@@ -45,7 +45,7 @@ class FailedTestsReporter extends Mocha.reporters.Base {
                 try {
                     reporter = require(reporterOptions.reporter);
                 }
-                catch (_) {
+                catch {
                     reporter = require(path.resolve(process.cwd(), reporterOptions.reporter));
                 }
             }

scripts/find-unused-diganostic-messages.mjs

@@ -18,7 +18,7 @@ startOfDiags.split(EOL).forEach(line => {
         execSync(`grep -rnw 'src' -e 'Diagnostics.${diagName}'`).toString();
         process.stdout.write(".");
     }
-    catch (error) {
+    catch {
         missingNames.push(diagName);
         process.stdout.write("x");
     }

src/compiler/sys.ts

@@ -1792,7 +1792,7 @@ export let sys: System = (() => {
             try {
                 buffer = _fs.readFileSync(fileName);
             }
-            catch (e) {
+            catch {
                 return undefined;
             }
             let len = buffer.length;
@@ -1863,7 +1863,7 @@ export let sys: System = (() => {
                                 continue;
                             }
                         }
-                        catch (e) {
+                        catch {
                             continue;
                         }
                     }
@@ -1882,7 +1882,7 @@ export let sys: System = (() => {
                 directories.sort();
                 return { files, directories };
             }
-            catch (e) {
+            catch {
                 return emptyFileSystemEntries;
             }
         }
@@ -1911,7 +1911,7 @@ export let sys: System = (() => {
                         return false;
                 }
             }
-            catch (e) {
+            catch {
                 return false;
             }
             finally {
@@ -1952,7 +1952,7 @@ export let sys: System = (() => {
             try {
                 return statSync(path)?.mtime;
             }
-            catch (e) {
+            catch {
                 return undefined;
             }
             finally {
@@ -1964,7 +1964,7 @@ export let sys: System = (() => {
             try {
                 _fs.utimesSync(path, time, time);
             }
-            catch (e) {
+            catch {
                 return;
             }
         }
@@ -1973,7 +1973,7 @@ export let sys: System = (() => {
             try {
                 return _fs.unlinkSync(path);
             }
-            catch (e) {
+            catch {
                 return;
             }
         }

src/compiler/utilitiesPublic.ts

@@ -723,7 +723,7 @@ export function validateLocaleAndSetLanguage(
         try {
             fileContents = sys.readFile(filePath);
         }
-        catch (e) {
+        catch {
             if (errors) {
                 errors.push(createCompilerDiagnostic(Diagnostics.Unable_to_open_file_0, filePath));
             }

src/compiler/watchUtilities.ts

@@ -198,7 +198,7 @@ export function createCachedDirectoryStructureHost(host: DirectoryStructureHost,
         try {
             return createCachedFileSystemEntries(rootDir, rootDirPath);
         }
-        catch (_e) {
+        catch {
             // If there is exception to read directories, dont cache the result and direct the calls to host
             Debug.assert(!cachedReadDirectoryResult.has(ensureTrailingDirectorySeparator(rootDirPath)));
             return undefined;

src/harness/harnessUtils.ts

@@ -41,7 +41,7 @@ export function readTestFile(path: string) {
     try {
         content = Harness.IO.readFile(Harness.userSpecifiedRoot + path);
     }
-    catch (err) {
+    catch {
         return undefined;
     }
 

src/tsserver/nodeServer.ts

@@ -124,7 +124,7 @@ export function initializeNodeSystem(): StartInput {
                 try {
                     this.fd = fs.openSync(this.logFilename, "w");
                 }
-                catch (_) {
+                catch {
                     // swallow the error and keep logging disabled if file cannot be opened
                 }
             }
@@ -280,7 +280,7 @@ export function initializeNodeSystem(): StartInput {
         const factory = require("./cancellationToken.js");
         cancellationToken = factory(sys.args);
     }
-    catch (e) {
+    catch {
         cancellationToken = ts.server.nullCancellationToken;
     }
 

src/typingsInstaller/nodeTypingsInstaller.ts

@@ -28,7 +28,7 @@ class FileLog implements ts.server.typingsInstaller.Log {
         try {
             fs.appendFileSync(this.logFile, `[${ts.server.nowString()}] ${text}${sys.newLine}`);
         }
-        catch (e) {
+        catch {
             this.logFile = undefined;
         }
     };