Defer checking:this param in object literal method

sandersn · sandersn · commit 9558c210f4c1 · 2017-02-08T15:09:29.000-08:00
This is completely ad-hoc, but it allows you to write `this: typeof o`
in an object literal and get the entire type.
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
@@ -15748,7 +15748,18 @@ namespace ts {
 
             checkTypeParameters(node.typeParameters);
 
-            forEach(node.parameters, checkParameter);
+            const isObjectLiteralMethodWithThis = isObjectLiteralMethod(node) &&
+                node.parameters &&
+                node.parameters.length &&
+                parameterIsThisKeyword(node.parameters[0]);
+            if (isObjectLiteralMethodWithThis) {
+                // defer checking on first one
+                checkNodeDeferred(node.parameters[0]); // .. this will surely work ..
+                forEach(node.parameters.slice(1), checkParameter);
+            }
+            else {
+                forEach(node.parameters, checkParameter);
+            }
 
             if (node.type) {
                 checkSourceElement(node.type);
diff --git a/tests/baselines/reference/recursion.js b/tests/baselines/reference/recursion.js
@@ -0,0 +1,33 @@
+//// [recursion.ts]
+let o = {
+    p: 12,
+    m(this: typeof o) {
+        let x = this.m(); // x: number
+        let y = this.p; // y: number
+        return this.p;
+    },
+    m2() {
+        return this.m() // this: any since it has no annotation
+    }
+}
+
+let x = o.m()  // x: number
+let y = o.m2() // y: any
+let p = o.p    // p: number
+
+
+//// [recursion.js]
+var o = {
+    p: 12,
+    m: function () {
+        var x = this.m(); // x: number
+        var y = this.p; // y: number
+        return this.p;
+    },
+    m2: function () {
+        return this.m(); // this: any since it has no annotation
+    }
+};
+var x = o.m(); // x: number
+var y = o.m2(); // y: any
+var p = o.p; // p: number
diff --git a/tests/baselines/reference/recursion.symbols b/tests/baselines/reference/recursion.symbols
@@ -0,0 +1,55 @@
+=== tests/cases/compiler/recursion.ts ===
+let o = {
+>o : Symbol(o, Decl(recursion.ts, 0, 3))
+
+    p: 12,
+>p : Symbol(p, Decl(recursion.ts, 0, 9))
+
+    m(this: typeof o) {
+>m : Symbol(m, Decl(recursion.ts, 1, 10))
+>this : Symbol(this, Decl(recursion.ts, 2, 6))
+>o : Symbol(o, Decl(recursion.ts, 0, 3))
+
+        let x = this.m(); // x: number
+>x : Symbol(x, Decl(recursion.ts, 3, 11))
+>this.m : Symbol(m, Decl(recursion.ts, 1, 10))
+>this : Symbol(this, Decl(recursion.ts, 2, 6))
+>m : Symbol(m, Decl(recursion.ts, 1, 10))
+
+        let y = this.p; // y: number
+>y : Symbol(y, Decl(recursion.ts, 4, 11))
+>this.p : Symbol(p, Decl(recursion.ts, 0, 9))
+>this : Symbol(this, Decl(recursion.ts, 2, 6))
+>p : Symbol(p, Decl(recursion.ts, 0, 9))
+
+        return this.p;
+>this.p : Symbol(p, Decl(recursion.ts, 0, 9))
+>this : Symbol(this, Decl(recursion.ts, 2, 6))
+>p : Symbol(p, Decl(recursion.ts, 0, 9))
+
+    },
+    m2() {
+>m2 : Symbol(m2, Decl(recursion.ts, 6, 6))
+
+        return this.m() // this: any since it has no annotation
+    }
+}
+
+let x = o.m()  // x: number
+>x : Symbol(x, Decl(recursion.ts, 12, 3))
+>o.m : Symbol(m, Decl(recursion.ts, 1, 10))
+>o : Symbol(o, Decl(recursion.ts, 0, 3))
+>m : Symbol(m, Decl(recursion.ts, 1, 10))
+
+let y = o.m2() // y: any
+>y : Symbol(y, Decl(recursion.ts, 13, 3))
+>o.m2 : Symbol(m2, Decl(recursion.ts, 6, 6))
+>o : Symbol(o, Decl(recursion.ts, 0, 3))
+>m2 : Symbol(m2, Decl(recursion.ts, 6, 6))
+
+let p = o.p    // p: number
+>p : Symbol(p, Decl(recursion.ts, 14, 3))
+>o.p : Symbol(p, Decl(recursion.ts, 0, 9))
+>o : Symbol(o, Decl(recursion.ts, 0, 3))
+>p : Symbol(p, Decl(recursion.ts, 0, 9))
+
diff --git a/tests/baselines/reference/recursion.types b/tests/baselines/reference/recursion.types
@@ -0,0 +1,64 @@
+=== tests/cases/compiler/recursion.ts ===
+let o = {
+>o : { p: number; m(this: any): number; m2(): any; }
+>{    p: 12,    m(this: typeof o) {        let x = this.m(); // x: number        let y = this.p; // y: number        return this.p;    },    m2() {        return this.m() // this: any since it has no annotation    }} : { p: number; m(this: any): number; m2(): any; }
+
+    p: 12,
+>p : number
+>12 : 12
+
+    m(this: typeof o) {
+>m : (this: { p: number; m(this: any): number; m2(): any; }) => number
+>this : { p: number; m(this: any): number; m2(): any; }
+>o : { p: number; m(this: any): number; m2(): any; }
+
+        let x = this.m(); // x: number
+>x : number
+>this.m() : number
+>this.m : (this: { p: number; m(this: any): number; m2(): any; }) => number
+>this : { p: number; m(this: any): number; m2(): any; }
+>m : (this: { p: number; m(this: any): number; m2(): any; }) => number
+
+        let y = this.p; // y: number
+>y : number
+>this.p : number
+>this : { p: number; m(this: any): number; m2(): any; }
+>p : number
+
+        return this.p;
+>this.p : number
+>this : { p: number; m(this: any): number; m2(): any; }
+>p : number
+
+    },
+    m2() {
+>m2 : () => any
+
+        return this.m() // this: any since it has no annotation
+>this.m() : any
+>this.m : any
+>this : any
+>m : any
+    }
+}
+
+let x = o.m()  // x: number
+>x : number
+>o.m() : number
+>o.m : (this: { p: number; m(this: any): number; m2(): any; }) => number
+>o : { p: number; m(this: any): number; m2(): any; }
+>m : (this: { p: number; m(this: any): number; m2(): any; }) => number
+
+let y = o.m2() // y: any
+>y : any
+>o.m2() : any
+>o.m2 : () => any
+>o : { p: number; m(this: any): number; m2(): any; }
+>m2 : () => any
+
+let p = o.p    // p: number
+>p : number
+>o.p : number
+>o : { p: number; m(this: any): number; m2(): any; }
+>p : number
+
diff --git a/tests/cases/compiler/recursion.ts b/tests/cases/compiler/recursion.ts
@@ -1,21 +1,15 @@
 let o = {
     p: 12,
     m(this: typeof o) {
+        let x = this.m(); // x: number
+        let y = this.p; // y: number
         return this.p;
-    }
-}
-let o2 = {
-    p: 12,
-    m() {
-        let x: typeof o2;
-        let y = this.p // nope, any
-        return x.p // ok???
-    }
+    },
     m2() {
-        return this.m() // still any!
+        return this.m() // this: any since it has no annotation
     }
 }
 
-let x = o2.m()
-let y = o2.m2()
-let p = o2.p
+let x = o.m()  // x: number
+let y = o.m2() // y: any
+let p = o.p    // p: number
