feat[isRequiredOf]: discover symbol properties in pred.predObj

is/__snapshots__/object_of_test.ts.snap

@@ -17,3 +17,19 @@ snapshot[`isObjectOf<T> > returns properly named predicate function 3`] = `
   })
 })"
 `;
+
+snapshot[`isObjectOf<T> > with symbol properties > returns properly named predicate function 1`] = `
+"isObjectOf({
+  a: isNumber,
+  b: isString,
+  Symbol(s): isBoolean
+})"
+`;
+
+snapshot[`isObjectOf<T> > with symbol properties > returns properly named predicate function 2`] = `
+"isObjectOf({
+  Symbol(a): isObjectOf({
+    Symbol(b): isObjectOf({Symbol(c): isBoolean})
+  })
+})"
+`;

is/__snapshots__/required_of_test.ts.snap

@@ -23,3 +23,27 @@ snapshot[`isRequiredOf<T> > returns properly named predicate function 2`] = `
   d: asReadonly(isString)
 })"
 `;
+
+snapshot[`isRequiredOf<T> > with symbol properties > returns properly named predicate function 1`] = `
+"isObjectOf({
+  a: isNumber,
+  Symbol(b): isUnionOf([
+    isString,
+    isUndefined
+  ]),
+  Symbol(c): isBoolean,
+  Symbol(d): asReadonly(isString)
+})"
+`;
+
+snapshot[`isRequiredOf<T> > with symbol properties > returns properly named predicate function 2`] = `
+"isObjectOf({
+  a: isNumber,
+  Symbol(b): isUnionOf([
+    isString,
+    isUndefined
+  ]),
+  Symbol(c): isBoolean,
+  Symbol(d): asReadonly(isString)
+})"
+`;

is/object_of.ts

@@ -48,7 +48,10 @@ export function isObjectOf<
           Array.isArray(x)
         ) return false;
         // Check each values
-        return Object.keys(predObj).every((k) => predObj[k]((x as T)[k]));
+        return [
+          ...Object.keys(predObj),
+          ...Object.getOwnPropertySymbols(predObj),
+        ].every((k) => predObj[k]((x as T)[k]));
       },
       "isObjectOf",
       predObj,

is/object_of_test.ts

@@ -152,4 +152,120 @@ Deno.test("isObjectOf<T>", async (t) => {
       });
     },
   );
+
+  await t.step("with symbol properties", async (t) => {
+    const s = Symbol("s");
+    const predObj = {
+      a: is.Number,
+      b: is.String,
+      [s]: is.Boolean,
+    };
+
+    await t.step("returns properly named predicate function", async (t) => {
+      await assertSnapshot(t, isObjectOf(predObj).name);
+      await assertSnapshot(
+        t,
+        isObjectOf({
+          [Symbol("a")]: isObjectOf({
+            [Symbol("b")]: isObjectOf({ [Symbol("c")]: is.Boolean }),
+          }),
+        }).name,
+      );
+    });
+
+    await t.step("returns true on T object", () => {
+      assertEquals(isObjectOf(predObj)({ a: 0, b: "a", [s]: true }), true);
+      assertEquals(
+        isObjectOf(predObj)({ a: 0, b: "a", [s]: true, d: "ignored" }),
+        true,
+        "Undefined properties are ignored",
+      );
+      assertEquals(
+        isObjectOf(predObj)({
+          a: 0,
+          b: "a",
+          [s]: true,
+          [Symbol("t")]: "ignored",
+        }),
+        true,
+        "Undefined symbol properties are ignored",
+      );
+      assertEquals(
+        isObjectOf(predObj)(
+          Object.assign(() => void 0, { a: 0, b: "a", [s]: true }),
+        ),
+        true,
+        "Function are treated as an object",
+      );
+    });
+
+    await t.step("returns false on non T object", () => {
+      assertEquals(isObjectOf(predObj)("a"), false, "Value is not an object");
+      assertEquals(
+        isObjectOf(predObj)({ a: 0, b: "a", [s]: "" }),
+        false,
+        "Object have a different type symbol property",
+      );
+      assertEquals(
+        isObjectOf(predObj)({ a: 0, b: "a" }),
+        false,
+        "Object does not have symbol property",
+      );
+      const arrayWithSymbolProp = ["ignored"];
+      // deno-lint-ignore no-explicit-any
+      (arrayWithSymbolProp as any)[s] = true;
+      assertEquals(
+        isObjectOf({ [s]: is.Boolean })(arrayWithSymbolProp),
+        false,
+        "Value is not an object",
+      );
+    });
+
+    await t.step("predicated type is correct", () => {
+      const a = Symbol("a");
+      const b = Symbol("b");
+      const c = Symbol("c");
+      const d = Symbol("d");
+      const e = Symbol("e");
+      const f = Symbol("f");
+      const predObj2 = {
+        [a]: as.Readonly(as.Optional(is.String)),
+        [b]: as.Optional(as.Readonly(is.String)),
+        [c]: as.Readonly(is.String),
+        [d]: as.Optional(is.String),
+        [e]: as.Unreadonly(as.Unoptional(as.Readonly(as.Optional(is.String)))),
+        [f]: as.Unoptional(as.Unreadonly(as.Optional(as.Readonly(is.String)))),
+      };
+      const x: unknown = {};
+
+      if (isObjectOf(predObj)(x)) {
+        assertType<
+          Equal<
+            typeof x,
+            {
+              a: number;
+              b: string;
+              [s]: boolean;
+            }
+          >
+        >(true);
+      }
+
+      if (isObjectOf(predObj2)(x)) {
+        assertType<
+          Equal<
+            typeof x,
+            {
+              readonly [a]?: string;
+              readonly [b]?: string;
+              readonly [c]: string;
+              [d]?: string;
+              [e]: string;
+              [f]: string;
+            }
+          >
+        >(true);
+      }
+    });
+  });
 });

is/required_of.ts

@@ -42,9 +42,14 @@ export function isRequiredOf<
 ):
   & Predicate<FlatType<Required<T>>>
   & IsPredObj<P> {
-  const predObj = Object.fromEntries(
-    Object.entries(pred.predObj).map(([k, v]) => [k, asUnoptional(v)]),
-  );
+  const keys = [
+    ...Object.keys(pred.predObj),
+    ...Object.getOwnPropertySymbols(pred.predObj),
+  ];
+  const predObj: Record<PropertyKey, Predicate<unknown>> = { ...pred.predObj };
+  for (const key of keys) {
+    predObj[key] = asUnoptional(predObj[key]);
+  }
   return isObjectOf(predObj) as
     & Predicate<FlatType<Required<T>>>
     & IsPredObj<P>;

is/required_of_test.ts

@@ -51,4 +51,59 @@ Deno.test("isRequiredOf<T>", async (t) => {
       >(true);
     }
   });
+
+  await t.step("with symbol properties", async (t) => {
+    const b = Symbol("b");
+    const c = Symbol("c");
+    const d = Symbol("d");
+    const pred = is.ObjectOf({
+      a: is.Number,
+      [b]: is.UnionOf([is.String, is.Undefined]),
+      [c]: as.Optional(is.Boolean),
+      [d]: as.Readonly(is.String),
+    });
+    await t.step("returns properly named predicate function", async (t) => {
+      await assertSnapshot(t, isRequiredOf(pred).name);
+      await assertSnapshot(t, isRequiredOf(isRequiredOf(pred)).name);
+    });
+
+    await t.step("returns true on Required<T> object", () => {
+      assertEquals(
+        isRequiredOf(pred)({ a: undefined, [b]: undefined, [c]: undefined }),
+        false,
+        "Object does not have required properties",
+      );
+      assertEquals(
+        isRequiredOf(pred)({}),
+        false,
+        "Object does not have required properties",
+      );
+    });
+
+    await t.step("returns false on non Required<T> object", () => {
+      assertEquals(isRequiredOf(pred)("a"), false, "Value is not an object");
+      assertEquals(
+        isRequiredOf(pred)({ a: 0, [b]: "a", [c]: "" }),
+        false,
+        "Object have a different type property",
+      );
+    });
+
+    await t.step("predicated type is correct", () => {
+      const a: unknown = { a: 0, [b]: "a", [c]: true };
+      if (isRequiredOf(pred)(a)) {
+        assertType<
+          Equal<
+            typeof a,
+            {
+              a: number;
+              [b]: string | undefined;
+              [c]: boolean;
+              readonly [d]: string;
+            }
+          >
+        >(true);
+      }
+    });
+  });
 });