Merge pull request #37727 from Kingwl/logical_assignment

Add logical assignment operator

tests/cases/conformance/esnext/logicalAssignment/logicalAssignment1.ts

@@ -0,0 +1,27 @@
+// @strict: true
+// @target: esnext, es2020, es2015
+declare let a: string | undefined
+declare let b: string | undefined
+declare let c: string | undefined
+
+declare let d: number | undefined
+declare let e: number | undefined
+declare let f: number | undefined
+
+declare let g: 0 | 1 | 42
+declare let h: 0 | 1 | 42
+declare let i: 0 | 1 | 42
+
+
+a &&= "foo"
+b ||= "foo"
+c ??= "foo"
+
+
+d &&= 42
+e ||= 42
+f ??= 42
+
+g &&= 42
+h ||= 42
+i ??= 42

tests/cases/conformance/esnext/logicalAssignment/logicalAssignment2.ts

@@ -0,0 +1,29 @@
+// @strict: true
+// @target: esnext, es2020, es2015
+interface A {
+    foo: {
+        bar(): {
+            baz: 0 | 1 | 42 | undefined | ''
+        }
+        baz: 0 | 1 | 42 | undefined | ''
+    }
+    baz: 0 | 1 | 42 | undefined | ''
+}
+
+declare const result: A
+declare const a: A
+declare const b: A
+declare const c: A
+
+a.baz &&= result.baz
+b.baz ||= result.baz
+c.baz ??= result.baz
+
+a.foo["baz"] &&= result.foo.baz
+b.foo["baz"] ||= result.foo.baz
+c.foo["baz"] ??= result.foo.baz
+
+a.foo.bar().baz &&= result.foo.bar().baz
+b.foo.bar().baz ||= result.foo.bar().baz
+c.foo.bar().baz ??= result.foo.bar().baz
+

tests/cases/conformance/esnext/logicalAssignment/logicalAssignment3.ts

@@ -0,0 +1,15 @@
+// @strict: true
+// @target: esnext, es2020, es2015
+interface A {
+    baz: 0 | 1 | 42 | undefined | ''
+}
+
+declare const result: A;
+declare const a: A;
+declare const b: A;
+declare const c: A;
+
+(a.baz) &&= result.baz;
+(b.baz) ||= result.baz;
+(c.baz) ??= result.baz;
+

tests/cases/conformance/esnext/logicalAssignment/logicalAssignment4.ts

@@ -0,0 +1,52 @@
+// @strict: true
+// @target: esnext, es2020, es2015
+// @allowUnreachableCode: false
+
+function foo1(results: number[] | undefined) {
+    (results ||= []).push(100);
+}
+
+function foo2(results: number[] | undefined) {
+    (results ??= []).push(100);
+}
+
+function foo3(results: number[] | undefined) {
+    results ||= [];
+    results.push(100);
+}
+
+function foo4(results: number[] | undefined) {
+    results ??= [];
+    results.push(100);
+}
+
+interface ThingWithOriginal {
+    name: string;
+    original?: ThingWithOriginal
+}
+declare const v: number
+function doSomethingWithAlias(thing: ThingWithOriginal | undefined, defaultValue: ThingWithOriginal | undefined) {
+    if (v === 1) {
+        if (thing &&= thing.original) {
+            thing.name;
+        }
+    }
+    else if (v === 2) {
+        if (thing &&= defaultValue) {
+            thing.name;
+            defaultValue.name
+        }
+    }
+    else if (v === 3) {
+        if (thing ||= defaultValue) {
+            thing.name;
+            defaultValue.name;
+        }
+    }
+    else {
+        if (thing ??= defaultValue) {
+            thing.name;
+            defaultValue.name;
+        }
+    }
+}

tests/cases/conformance/esnext/logicalAssignment/logicalAssignment5.ts

@@ -0,0 +1,32 @@
+// @strict: true
+// @target: esnext, es2020, es2015
+
+function foo1 (f?: (a: number) => void) {
+    f ??= (a => a)
+    f(42)
+}
+
+function foo2 (f?: (a: number) => void) {
+    f ||= (a => a)
+    f(42)
+}
+
+function foo3 (f?: (a: number) => void) {
+    f &&= (a => a)
+    f(42)
+}
+
+function bar1 (f?: (a: number) => void) {
+    f ??= (f.toString(), (a => a))
+    f(42)
+}
+
+function bar2 (f?: (a: number) => void) {
+    f ||= (f.toString(), (a => a))
+    f(42)
+}
+
+function bar3 (f?: (a: number) => void) {
+    f &&= (f.toString(), (a => a))
+    f(42)
+}

tests/cases/conformance/esnext/logicalAssignment/logicalAssignment6.ts

@@ -0,0 +1,14 @@
+// @strict: true
+// @target: esnext, es2020, es2015
+
+function foo1(results: number[] | undefined, results1: number[] | undefined) {
+    (results ||= (results1 ||= [])).push(100);
+}
+
+function foo2(results: number[] | undefined, results1: number[] | undefined) {
+    (results ??= (results1 ??= [])).push(100);
+}
+
+function foo3(results: number[] | undefined, results1: number[] | undefined) {
+    (results &&= (results1 &&= [])).push(100);
+}

tests/cases/conformance/esnext/logicalAssignment/logicalAssignment7.ts

@@ -0,0 +1,14 @@
+// @strict: true
+// @target: esnext, es2020, es2015
+
+function foo1(results: number[] | undefined, results1: number[] | undefined) {
+    (results ||= results1 ||= []).push(100);
+}
+
+function foo2(results: number[] | undefined, results1: number[] | undefined) {
+    (results ??= results1 ??= []).push(100);
+}
+
+function foo3(results: number[] | undefined, results1: number[] | undefined) {
+    (results &&= results1 &&= []).push(100);
+}

tests/cases/conformance/esnext/logicalAssignment/logicalAssignment8.ts

@@ -0,0 +1,16 @@
+// @strict: true
+// @target: esnext, es2020, es2015
+
+declare const bar: { value?: number[] } | undefined
+
+function foo1(results: number[] | undefined) {
+    (results ||= bar?.value ?? []).push(100);
+}
+
+function foo2(results: number[] | undefined) {
+    (results ??= bar?.value ?? []).push(100);
+}
+
+function foo3(results: number[] | undefined) {
+    (results &&= bar?.value ?? []).push(100);
+}