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

8 files changed, 65 insertions, 65 deletions

diff --git a/std/testing/README.md b/std/testing/README.md
index e2bd90b24..8d02f9d79 100644
--- a/std/testing/README.md
+++ b/std/testing/README.md
@@ -92,11 +92,9 @@ Using `assertThrows()`:
 
 ```ts
 test(function doesThrow(): void {
-  assertThrows(
-    (): void => {
-      throw new TypeError("hello world!");
-    }
-  );
+  assertThrows((): void => {
+    throw new TypeError("hello world!");
+  });
   assertThrows((): void => {
     throw new TypeError("hello world!");
   }, TypeError);
@@ -111,11 +109,9 @@ test(function doesThrow(): void {
 
 // This test will not pass
 test(function fails(): void {
-  assertThrows(
-    (): void => {
-      console.log("Hello world");
-    }
-  );
+  assertThrows((): void => {
+    console.log("Hello world");
+  });
 });
 ```
 
diff --git a/std/testing/asserts.ts b/std/testing/asserts.ts
index ceac52dbd..3ae45454c 100644
--- a/std/testing/asserts.ts
+++ b/std/testing/asserts.ts
@@ -56,12 +56,10 @@ function buildMessage(diffResult: ReadonlyArray<DiffResult<string>>): string[] {
   );
   messages.push("");
   messages.push("");
-  diffResult.forEach(
-    (result: DiffResult<string>): void => {
-      const c = createColor(result.type);
-      messages.push(c(`${createSign(result.type)}${result.value}`));
-    }
-  );
+  diffResult.forEach((result: DiffResult<string>): void => {
+    const c = createColor(result.type);
+    messages.push(c(`${createSign(result.type)}${result.value}`));
+  });
   messages.push("");
 
   return messages;
@@ -131,7 +129,7 @@ export function equal(c: unknown, d: unknown): boolean {
 }
 
 /** Make an assertion, if not `true`, then throw. */
-export function assert(expr: boolean, msg = ""): void {
+export function assert(expr: unknown, msg = ""): asserts expr {
   if (!expr) {
     throw new AssertionError(msg);
   }
diff --git a/std/testing/asserts_test.ts b/std/testing/asserts_test.ts
index 956d66e3e..be0502ce6 100644
--- a/std/testing/asserts_test.ts
+++ b/std/testing/asserts_test.ts
@@ -51,8 +51,14 @@ test(function testingEqual(): void {
   assert(equal(new Map(), new Map()));
   assert(
     equal(
-      new Map([["foo", "bar"], ["baz", "baz"]]),
-      new Map([["foo", "bar"], ["baz", "baz"]])
+      new Map([
+        ["foo", "bar"],
+        ["baz", "baz"]
+      ]),
+      new Map([
+        ["foo", "bar"],
+        ["baz", "baz"]
+      ])
     )
   );
   assert(
@@ -69,14 +75,26 @@ test(function testingEqual(): void {
   );
   assert(
     equal(
-      new Map([["foo", "bar"], ["baz", "qux"]]),
-      new Map([["baz", "qux"], ["foo", "bar"]])
+      new Map([
+        ["foo", "bar"],
+        ["baz", "qux"]
+      ]),
+      new Map([
+        ["baz", "qux"],
+        ["foo", "bar"]
+      ])
     )
   );
   assert(equal(new Map([["foo", ["bar"]]]), new Map([["foo", ["bar"]]])));
   assert(!equal(new Map([["foo", "bar"]]), new Map([["bar", "baz"]])));
   assert(
-    !equal(new Map([["foo", "bar"]]), new Map([["foo", "bar"], ["bar", "baz"]]))
+    !equal(
+      new Map([["foo", "bar"]]),
+      new Map([
+        ["foo", "bar"],
+        ["bar", "baz"]
+      ])
+    )
   );
   assert(
     !equal(
diff --git a/std/testing/diff.ts b/std/testing/diff.ts
index dd544ac24..38d632e9a 100644
--- a/std/testing/diff.ts
+++ b/std/testing/diff.ts
@@ -133,7 +133,7 @@ export default function diff<T>(A: T[], B: T[]): Array<DiffResult<T>> {
     k: number,
     M: number
   ): FarthestPoint {
-    if (slide && slide.y === -1 && (down && down.y === -1))
+    if (slide && slide.y === -1 && down && down.y === -1)
       return { y: 0, id: 0 };
     if (
       (down && down.y === -1) ||
diff --git a/std/testing/format.ts b/std/testing/format.ts
index 28937d567..953347c27 100644
--- a/std/testing/format.ts
+++ b/std/testing/format.ts
@@ -360,13 +360,11 @@ const getKeysOfEnumerableProperties = (object: {}): Array<string | symbol> => {
   const keys: Array<string | symbol> = Object.keys(object).sort();
 
   if (Object.getOwnPropertySymbols) {
-    Object.getOwnPropertySymbols(object).forEach(
-      (symbol): void => {
-        if (Object.getOwnPropertyDescriptor(object, symbol)!.enumerable) {
-          keys.push(symbol);
-        }
+    Object.getOwnPropertySymbols(object).forEach((symbol): void => {
+      if (Object.getOwnPropertyDescriptor(object, symbol)!.enumerable) {
+        keys.push(symbol);
       }
-    );
+    });
   }
 
   return keys;
diff --git a/std/testing/mod.ts b/std/testing/mod.ts
index bd7642b81..3b6386d5b 100644
--- a/std/testing/mod.ts
+++ b/std/testing/mod.ts
@@ -203,14 +203,12 @@ function report(result: TestResult): void {
 }
 
 function printFailedSummary(results: TestResults): void {
-  results.cases.forEach(
-    (v): void => {
-      if (!v.ok) {
-        console.error(`${RED_BG_FAIL} ${red(v.name)}`);
-        console.error(v.error);
-      }
+  results.cases.forEach((v): void => {
+    if (!v.ok) {
+      console.error(`${RED_BG_FAIL} ${red(v.name)}`);
+      console.error(v.error);
     }
-  );
+  });
 }
 
 function printResults(
@@ -321,14 +319,12 @@ async function runTestsSerial(
       print(
         GREEN_OK + "     " + name + " " + promptTestTime(end - start, true)
       );
-      results.cases.forEach(
-        (v): void => {
-          if (v.name === name) {
-            v.ok = true;
-            v.printed = true;
-          }
+      results.cases.forEach((v): void => {
+        if (v.name === name) {
+          v.ok = true;
+          v.printed = true;
         }
-      );
+      });
     } catch (err) {
       if (disableLog) {
         print(CLEAR_LINE, false);
@@ -336,15 +332,13 @@ async function runTestsSerial(
       print(`${RED_FAILED} ${name}`);
       print(err.stack);
       stats.failed++;
-      results.cases.forEach(
-        (v): void => {
-          if (v.name === name) {
-            v.error = err;
-            v.ok = false;
-            v.printed = true;
-          }
+      results.cases.forEach((v): void => {
+        if (v.name === name) {
+          v.error = err;
+          v.ok = false;
+          v.printed = true;
         }
-      );
+      });
       if (exitOnFail) {
         break;
       }
diff --git a/std/testing/runner.ts b/std/testing/runner.ts
index 48bc4c9c3..d0e9546f5 100755
--- a/std/testing/runner.ts
+++ b/std/testing/runner.ts
@@ -204,8 +204,8 @@ async function main(): Promise<void> {
 
   const include =
     parsedArgs._.length > 0
-      ? (parsedArgs._ as string[]).flatMap(
-          (fileGlob: string): string[] => fileGlob.split(",")
+      ? (parsedArgs._ as string[]).flatMap((fileGlob: string): string[] =>
+          fileGlob.split(",")
         )
       : ["."];
   const exclude =
diff --git a/std/testing/test.ts b/std/testing/test.ts
index 93233f7cc..dd6d772f6 100644
--- a/std/testing/test.ts
+++ b/std/testing/test.ts
@@ -51,12 +51,10 @@ test(function testingAssertNotStrictEqual(): void {
 
 test(function testingDoesThrow(): void {
   let count = 0;
-  assertThrows(
-    (): void => {
-      count++;
-      throw new Error();
-    }
-  );
+  assertThrows((): void => {
+    count++;
+    throw new Error();
+  });
   assert(count === 1);
 });
 
@@ -64,12 +62,10 @@ test(function testingDoesNotThrow(): void {
   let count = 0;
   let didThrow = false;
   try {
-    assertThrows(
-      (): void => {
-        count++;
-        console.log("Hello world");
-      }
-    );
+    assertThrows((): void => {
+      count++;
+      console.log("Hello world");
+    });
   } catch (e) {
     assert(e.message === "Expected function to throw.");
     didThrow = true;