TS: Fix strict issues in src/jsutils

src/jsutils/__tests__/identityFunc-test.ts

@@ -5,7 +5,7 @@ import { identityFunc } from '../identityFunc';
 
 describe('identityFunc', () => {
   it('returns the first argument it receives', () => {
-    // @ts-expect-error FIXME: TS Conversion
+    // @ts-expect-error (Expects an argument)
     expect(identityFunc()).to.equal(undefined);
     expect(identityFunc(undefined)).to.equal(undefined);
     expect(identityFunc(null)).to.equal(null);

src/jsutils/__tests__/inspect-test.ts

@@ -132,13 +132,13 @@ describe('inspect', () => {
       '{ self: [Circular], deepSelf: { self: [Circular] } }',
     );
 
-    const array = [];
+    const array: any = [];
     array[0] = array;
     array[1] = [array];
 
     expect(inspect(array)).to.equal('[[Circular], [[Circular]]]');
 
-    const mixed = { array: [] };
+    const mixed: any = { array: [] };
     mixed.array[0] = mixed;
 
     expect(inspect(mixed)).to.equal('{ array: [[Circular]] }');
@@ -165,14 +165,21 @@ describe('inspect', () => {
 
     expect(inspect([[new Foo()]])).to.equal('[[[Foo]]]');
 
-    Foo.prototype[Symbol.toStringTag] = 'Bar';
-    expect(inspect([[new Foo()]])).to.equal('[[[Bar]]]');
+    class Foo2 {
+      foo: string;
+
+      [Symbol.toStringTag] = 'Bar';
+
+      constructor() {
+        this.foo = 'bar';
+      }
+    }
+    expect(inspect([[new Foo2()]])).to.equal('[[[Bar]]]');
 
     // eslint-disable-next-line func-names
-    const objectWithoutClassName = new (function () {
-      // eslint-disable-next-line @typescript-eslint/no-invalid-this
+    const objectWithoutClassName = new (function (this: any) {
       this.foo = 1;
-    })();
+    } as any)();
     expect(inspect([[objectWithoutClassName]])).to.equal('[[[Object]]]');
   });
 });

src/jsutils/didYouMean.ts

@@ -12,10 +12,9 @@ export function didYouMean(
   firstArg: string | ReadonlyArray<string>,
   secondArg?: ReadonlyArray<string>,
 ) {
-  const [subMessage, suggestionsArg] =
-    typeof firstArg === 'string'
-      ? [firstArg, secondArg]
-      : [undefined, firstArg];
+  const [subMessage, suggestionsArg] = secondArg
+    ? [firstArg as string, secondArg]
+    : [undefined, firstArg as ReadonlyArray<string>];
 
   let message = ' Did you mean ';
   if (subMessage) {

src/jsutils/inspect.ts

@@ -22,7 +22,7 @@ function formatValue(value: unknown, seenValues: Array<unknown>): string {
 }
 
 function formatObjectValue(
-  value: Object,
+  value: object | null,
   previouslySeenValues: Array<unknown>,
 ): string {
   if (value === null) {
@@ -35,10 +35,8 @@ function formatObjectValue(
 
   const seenValues = [...previouslySeenValues, value];
 
-  // @ts-expect-error FIXME: TS Conversion
-  if (typeof value.toJSON === 'function') {
-    // @ts-expect-error FIXME: TS Conversion
-    const jsonValue = (value.toJSON as () => unknown)();
+  if (isJSONable(value)) {
+    const jsonValue = value.toJSON();
 
     // check for infinite recursion
     if (jsonValue !== value) {
@@ -53,7 +51,11 @@ function formatObjectValue(
   return formatObject(value, seenValues);
 }
 
-function formatObject(object: Object, seenValues: Array<unknown>): string {
+function isJSONable(value: any): value is { toJSON: () => unknown } {
+  return typeof value.toJSON === 'function';
+}
+
+function formatObject(object: object, seenValues: Array<unknown>): string {
   const entries = Object.entries(object);
   if (entries.length === 0) {
     return '{}';
@@ -98,7 +100,7 @@ function formatArray(
   return '[' + items.join(', ') + ']';
 }
 
-function getObjectTag(object: Object): string {
+function getObjectTag(object: object): string {
   const tag = Object.prototype.toString
     .call(object)
     .replace(/^\[object /, '')

src/jsutils/isAsyncIterable.ts

@@ -3,7 +3,7 @@
  * implementing a `Symbol.asyncIterator` method.
  */
 export function isAsyncIterable(
-  maybeAsyncIterable: unknown,
+  maybeAsyncIterable: any,
 ): maybeAsyncIterable is AsyncIterable<unknown> {
   return typeof maybeAsyncIterable?.[Symbol.asyncIterator] === 'function';
 }

src/jsutils/isIterableObject.ts

@@ -15,7 +15,7 @@
  * isIterableObject({ length: 1, 0: 'Alpha' }) // false
  */
 export function isIterableObject(
-  maybeIterable: unknown,
+  maybeIterable: any,
 ): maybeIterable is Iterable<unknown> {
   return (
     typeof maybeIterable === 'object' &&

src/jsutils/isPromise.ts

@@ -2,7 +2,6 @@
  * Returns true if the value acts like a Promise, i.e. has a "then" function,
  * otherwise returns false.
  */
-export function isPromise(value: unknown): value is Promise<unknown> {
-  // eslint-disable-next-line @typescript-eslint/dot-notation
-  return typeof value?.['then'] === 'function';
+export function isPromise(value: any): value is Promise<unknown> {
+  return typeof value?.then === 'function';
 }

src/jsutils/memoize3.ts

@@ -7,7 +7,7 @@ export function memoize3<
   A3 extends object,
   R,
 >(fn: (a1: A1, a2: A2, a3: A3) => R): (a1: A1, a2: A2, a3: A3) => R {
-  let cache0;
+  let cache0: WeakMap<A1, WeakMap<A2, WeakMap<A3, R>>>;
 
   return function memoized(a1, a2, a3) {
     if (cache0 === undefined) {