feat: Number.isInteger() (#1518)

scarf005 · web-flow · commit e0e56fe38942 · 2023-11-18T15:27:15.000+01:00
diff --git a/src/LuaLib.ts b/src/LuaLib.ts
@@ -63,6 +63,7 @@ export enum LuaLibFeature {
     New = "New",
     Number = "Number",
     NumberIsFinite = "NumberIsFinite",
+    NumberIsInteger = "NumberIsInteger",
     NumberIsNaN = "NumberIsNaN",
     NumberParseInt = "ParseInt",
     NumberParseFloat = "ParseFloat",
diff --git a/src/lualib/NumberIsInteger.ts b/src/lualib/NumberIsInteger.ts
@@ -0,0 +1,6 @@
+import { __TS__NumberIsFinite } from "./NumberIsFinite";
+
+/// https://tc39.es/ecma262/multipage/numbers-and-dates.html#sec-number.isinteger
+export function __TS__NumberIsInteger(this: void, value: unknown): boolean {
+    return __TS__NumberIsFinite(value) && math.floor(value as number) === (value as number);
+}
diff --git a/src/transformation/builtins/number.ts b/src/transformation/builtins/number.ts
@@ -118,6 +118,8 @@ export function transformNumberConstructorCall(
     const parameters = transformArguments(context, node.arguments);
     const methodName = calledMethod.name.text;
     switch (methodName) {
+        case "isInteger":
+            return transformLuaLibFunction(context, LuaLibFeature.NumberIsInteger, node, ...parameters);
         case "isNaN":
             return transformLuaLibFunction(context, LuaLibFeature.NumberIsNaN, node, ...parameters);
         case "isFinite":
diff --git a/test/unit/builtins/numbers.spec.ts b/test/unit/builtins/numbers.spec.ts
@@ -46,6 +46,10 @@ describe("Number", () => {
     test.each(cases)("isFinite(%p)", value => {
         util.testExpressionTemplate`Number.isFinite(${value} as any)`.expectToMatchJsResult();
     });
+
+    test.each(cases)("isInteger(%p)", value => {
+        util.testExpressionTemplate`Number.isInteger(${value} as any)`.expectToMatchJsResult();
+    });
 });
 
 const toStringRadixes = [undefined, 10, 2, 8, 9, 16, 17, 36, 36.9];
