11 files changed, 42 insertions, 10 deletions
diff --git a/cli/tests/testdata/070_location.ts b/cli/tests/testdata/070_location.ts
index 61256dcbc..149de5423 100644
--- a/cli/tests/testdata/070_location.ts
+++ b/cli/tests/testdata/070_location.ts
@@ -4,5 +4,7 @@ console.log(location);
 try {
   location.hostname = "bar";
 } catch (error) {
-  console.log(error.toString());
+  if (error instanceof Error) {
+    console.log(error.toString());
+  }
 }
diff --git a/cli/tests/testdata/085_dynamic_import_async_error.ts b/cli/tests/testdata/085_dynamic_import_async_error.ts
index aa5ff7277..998e7ed3e 100644
--- a/cli/tests/testdata/085_dynamic_import_async_error.ts
+++ b/cli/tests/testdata/085_dynamic_import_async_error.ts
@@ -1,5 +1,7 @@
 try {
   await import("./delayed_error.ts");
 } catch (error) {
-  console.log(`Caught: ${error.stack}`);
+  if (error instanceof Error) {
+    console.log(`Caught: ${error.stack}`);
+  }
 }
diff --git a/cli/tests/testdata/086_dynamic_import_already_rejected.ts b/cli/tests/testdata/086_dynamic_import_already_rejected.ts
index 359db670c..249de8d8b 100644
--- a/cli/tests/testdata/086_dynamic_import_already_rejected.ts
+++ b/cli/tests/testdata/086_dynamic_import_already_rejected.ts
@@ -1,11 +1,15 @@
 try {
   await import("./error_001.ts");
 } catch (error) {
-  console.log(`Caught: ${error.stack}`);
+  if (error instanceof Error) {
+    console.log(`Caught: ${error.stack}`);
+  }
 }
 
 try {
   await import("./error_001.ts");
 } catch (error) {
-  console.log(`Caught: ${error.stack}`);
+  if (error instanceof Error) {
+    console.log(`Caught: ${error.stack}`);
+  }
 }
diff --git a/cli/tests/testdata/error_019_stack_function.ts b/cli/tests/testdata/error_019_stack_function.ts
index c5eeae8f4..a6a69d146 100644
--- a/cli/tests/testdata/error_019_stack_function.ts
+++ b/cli/tests/testdata/error_019_stack_function.ts
@@ -5,6 +5,8 @@ function foo(): never {
 try {
   foo();
 } catch (error) {
-  console.log(error.stack);
+  if (error instanceof Error) {
+    console.log(error.stack);
+  }
   throw error;
 }
diff --git a/cli/tests/testdata/error_020_stack_constructor.ts b/cli/tests/testdata/error_020_stack_constructor.ts
index 49988280b..526d1a661 100644
--- a/cli/tests/testdata/error_020_stack_constructor.ts
+++ b/cli/tests/testdata/error_020_stack_constructor.ts
@@ -7,6 +7,8 @@ class A {
 try {
   new A();
 } catch (error) {
-  console.log(error.stack);
+  if (error instanceof Error) {
+    console.log(error.stack);
+  }
   throw error;
 }
diff --git a/cli/tests/testdata/error_021_stack_method.ts b/cli/tests/testdata/error_021_stack_method.ts
index a52d00deb..b6ebe1f5e 100644
--- a/cli/tests/testdata/error_021_stack_method.ts
+++ b/cli/tests/testdata/error_021_stack_method.ts
@@ -7,6 +7,8 @@ class A {
 try {
   new A().m();
 } catch (error) {
-  console.log(error.stack);
+  if (error instanceof Error) {
+    console.log(error.stack);
+  }
   throw error;
 }
diff --git a/cli/tests/testdata/error_023_stack_async.ts b/cli/tests/testdata/error_023_stack_async.ts
index 99e676e26..fdabaa5df 100644
--- a/cli/tests/testdata/error_023_stack_async.ts
+++ b/cli/tests/testdata/error_023_stack_async.ts
@@ -7,6 +7,8 @@ const p = (async () => {
 try {
   await p;
 } catch (error) {
-  console.log(error.stack);
+  if (error instanceof Error) {
+    console.log(error.stack);
+  }
   throw error;
 }
diff --git a/cli/tests/testdata/error_024_stack_promise_all.ts b/cli/tests/testdata/error_024_stack_promise_all.ts
index ddaf0dbaa..8ca7b203c 100644
--- a/cli/tests/testdata/error_024_stack_promise_all.ts
+++ b/cli/tests/testdata/error_024_stack_promise_all.ts
@@ -9,6 +9,8 @@ const p = Promise.all([
 try {
   await p;
 } catch (error) {
-  console.log(error.stack);
+  if (error instanceof Error) {
+    console.log(error.stack);
+  }
   throw error;
 }
diff --git a/cli/tests/testdata/resolve_dns.ts b/cli/tests/testdata/resolve_dns.ts
index e4a50f7dc..1757c938e 100644
--- a/cli/tests/testdata/resolve_dns.ts
+++ b/cli/tests/testdata/resolve_dns.ts
@@ -38,5 +38,9 @@ console.log(JSON.stringify(txt));
 try {
   await Deno.resolveDns("not-found-example.com", "A", nameServer);
 } catch (e) {
-  console.log(`Error ${e.name} thrown for not-found-example.com`);
+  console.log(
+    `Error ${
+      e instanceof Error ? e.name : "[non-error]"
+    } thrown for not-found-example.com`,
+  );
 }
diff --git a/cli/tests/testdata/useUnknownInCatchVariables.ts b/cli/tests/testdata/useUnknownInCatchVariables.ts
new file mode 100644
index 000000000..abab554a4
--- /dev/null
+++ b/cli/tests/testdata/useUnknownInCatchVariables.ts
@@ -0,0 +1,5 @@
+try {
+  throw new Error();
+} catch (e) {
+  console.log(e.message);
+}
diff --git a/cli/tests/testdata/useUnknownInCatchVariables.ts.out b/cli/tests/testdata/useUnknownInCatchVariables.ts.out
new file mode 100644
index 000000000..3c29d3229
--- /dev/null
+++ b/cli/tests/testdata/useUnknownInCatchVariables.ts.out
@@ -0,0 +1,5 @@
+[WILDCARD]
+error: TS2571 [ERROR]: Object is of type 'unknown'.
+  console.log(e.message);
+              ^
+    at file://[WILDCARD]/useUnknownInCatchVariables.ts:4:15