Update to TypeScript 3.7 (#3275)

and update to prettier 1.19

Also, update `assert()` and remove not null assertions where possibly
in `cli`.

Closes #3273

1 files changed, 4 insertions, 6 deletions

diff --git a/cli/js/fetch_test.ts b/cli/js/fetch_test.ts
index 1b9450dcd..299cbe05f 100644
--- a/cli/js/fetch_test.ts
+++ b/cli/js/fetch_test.ts
@@ -60,12 +60,10 @@ testPerm({ net: true }, async function fetchBlob(): Promise<void> {
 testPerm({ net: true }, async function fetchBodyUsed(): Promise<void> {
   const response = await fetch("http://localhost:4545/cli/tests/fixture.json");
   assertEquals(response.bodyUsed, false);
-  assertThrows(
-    (): void => {
-      // Assigning to read-only property throws in the strict mode.
-      response.bodyUsed = true;
-    }
-  );
+  assertThrows((): void => {
+    // Assigning to read-only property throws in the strict mode.
+    response.bodyUsed = true;
+  });
   await response.blob();
   assertEquals(response.bodyUsed, true);
 });