Merge pull request #13358 from Microsoft/iifeMissingArguments

Infer optional types for IIFE parameters with missing arguments

src/compiler/checker.ts

@@ -5058,9 +5058,10 @@ namespace ts {
             if (!links.resolvedSignature) {
                 const parameters: Symbol[] = [];
                 let hasLiteralTypes = false;
-                let minArgumentCount = -1;
+                let minArgumentCount = 0;
                 let thisParameter: Symbol = undefined;
                 let hasThisParameter: boolean;
+                const iife = getImmediatelyInvokedFunctionExpression(declaration);
                 const isJSConstructSignature = isJSDocConstructSignature(declaration);
 
                 // If this is a JSDoc construct signature, then skip the first parameter in the
@@ -5087,14 +5088,12 @@ namespace ts {
                         hasLiteralTypes = true;
                     }
 
-                    if (param.initializer || param.questionToken || param.dotDotDotToken || isJSDocOptionalParameter(param)) {
-                        if (minArgumentCount < 0) {
-                            minArgumentCount = i - (hasThisParameter ? 1 : 0);
-                        }
-                    }
-                    else {
-                        // If we see any required parameters, it means the prior ones were not in fact optional.
-                        minArgumentCount = -1;
+                    // Record a new minimum argument count if this is not an optional parameter
+                    const isOptionalParameter = param.initializer || param.questionToken || param.dotDotDotToken ||
+                        iife && parameters.length > iife.arguments.length && !param.type ||
+                        isJSDocOptionalParameter(param);
+                    if (!isOptionalParameter) {
+                        minArgumentCount = parameters.length;
                     }
                 }
 
@@ -5109,13 +5108,6 @@ namespace ts {
                     }
                 }
 
-                if (minArgumentCount < 0) {
-                    minArgumentCount = declaration.parameters.length - (hasThisParameter ? 1 : 0);
-                }
-                if (isJSConstructSignature) {
-                    minArgumentCount--;
-                }
-
                 const classType = declaration.kind === SyntaxKind.Constructor ?
                     getDeclaredTypeOfClassOrInterface(getMergedSymbol((<ClassDeclaration>declaration.parent).symbol))
                     : undefined;
@@ -10935,23 +10927,23 @@ namespace ts {
             const func = parameter.parent;
             if (isContextSensitiveFunctionOrObjectLiteralMethod(func)) {
                 const iife = getImmediatelyInvokedFunctionExpression(func);
-                if (iife) {
+                if (iife && iife.arguments) {
                     const indexOfParameter = indexOf(func.parameters, parameter);
-                    if (iife.arguments && indexOfParameter < iife.arguments.length) {
-                        if (parameter.dotDotDotToken) {
-                            const restTypes: Type[] = [];
-                            for (let i = indexOfParameter; i < iife.arguments.length; i++) {
-                                restTypes.push(getWidenedLiteralType(checkExpression(iife.arguments[i])));
-                            }
-                            return createArrayType(getUnionType(restTypes));
+                    if (parameter.dotDotDotToken) {
+                        const restTypes: Type[] = [];
+                        for (let i = indexOfParameter; i < iife.arguments.length; i++) {
+                            restTypes.push(getWidenedLiteralType(checkExpression(iife.arguments[i])));
                         }
-                        const links = getNodeLinks(iife);
-                        const cached = links.resolvedSignature;
-                        links.resolvedSignature = anySignature;
-                        const type = getWidenedLiteralType(checkExpression(iife.arguments[indexOfParameter]));
-                        links.resolvedSignature = cached;
-                        return type;
+                        return restTypes.length ? createArrayType(getUnionType(restTypes)) : undefined;
                     }
+                    const links = getNodeLinks(iife);
+                    const cached = links.resolvedSignature;
+                    links.resolvedSignature = anySignature;
+                    const type = indexOfParameter < iife.arguments.length ?
+                        getWidenedLiteralType(checkExpression(iife.arguments[indexOfParameter])) :
+                        parameter.initializer ? undefined : undefinedWideningType;
+                    links.resolvedSignature = cached;
+                    return type;
                 }
                 const contextualSignature = getContextualSignature(func);
                 if (contextualSignature) {

tests/baselines/reference/contextuallyTypedIife.js

@@ -28,6 +28,9 @@
 // contextually typed parameters.
 let twelve = (f => f(12))(i => i);
 let eleven = (o => o.a(11))({ a: function(n) { return n; } });
+// missing arguments
+(function(x, undefined) { return x; })(42);
+((x, y, z) => 42)();
 
 
 //// [contextuallyTypedIife.js]
@@ -102,3 +105,6 @@ let eleven = (o => o.a(11))({ a: function(n) { return n; } });
 // contextually typed parameters.
 var twelve = (function (f) { return f(12); })(function (i) { return i; });
 var eleven = (function (o) { return o.a(11); })({ a: function (n) { return n; } });
+// missing arguments
+(function (x, undefined) { return x; })(42);
+(function (x, y, z) { return 42; })();

tests/baselines/reference/contextuallyTypedIife.symbols

@@ -119,3 +119,14 @@ let eleven = (o => o.a(11))({ a: function(n) { return n; } });
 >n : Symbol(n, Decl(contextuallyTypedIife.ts, 28, 42))
 >n : Symbol(n, Decl(contextuallyTypedIife.ts, 28, 42))
 
+// missing arguments
+(function(x, undefined) { return x; })(42);
+>x : Symbol(x, Decl(contextuallyTypedIife.ts, 30, 10))
+>undefined : Symbol(undefined, Decl(contextuallyTypedIife.ts, 30, 12))
+>x : Symbol(x, Decl(contextuallyTypedIife.ts, 30, 10))
+
+((x, y, z) => 42)();
+>x : Symbol(x, Decl(contextuallyTypedIife.ts, 31, 2))
+>y : Symbol(y, Decl(contextuallyTypedIife.ts, 31, 4))
+>z : Symbol(z, Decl(contextuallyTypedIife.ts, 31, 7))
+

tests/baselines/reference/contextuallyTypedIife.types

@@ -250,3 +250,22 @@ let eleven = (o => o.a(11))({ a: function(n) { return n; } });
 >n : any
 >n : any
 
+// missing arguments
+(function(x, undefined) { return x; })(42);
+>(function(x, undefined) { return x; })(42) : number
+>(function(x, undefined) { return x; }) : (x: number, undefined: any) => number
+>function(x, undefined) { return x; } : (x: number, undefined: any) => number
+>x : number
+>undefined : any
+>x : number
+>42 : 42
+
+((x, y, z) => 42)();
+>((x, y, z) => 42)() : number
+>((x, y, z) => 42) : (x: any, y: any, z: any) => number
+>(x, y, z) => 42 : (x: any, y: any, z: any) => number
+>x : any
+>y : any
+>z : any
+>42 : 42
+

tests/baselines/reference/contextuallyTypedIifeStrict.js

@@ -0,0 +1,110 @@
+//// [contextuallyTypedIifeStrict.ts]
+// arrow
+(jake => { })("build");
+// function expression
+(function (cats) { })("lol");
+// Lots of Irritating Superfluous Parentheses
+(function (x) { } ("!"));
+((((function (y) { }))))("-");
+// multiple arguments
+((a, b, c) => { })("foo", 101, false);
+// default parameters
+((m = 10) => m + 1)(12);
+((n = 10) => n + 1)();
+// optional parameters
+((j?) => j + 1)(12);
+((k?) => k + 1)();
+((l, o?) => l + o)(12); // o should be any
+// rest parameters
+((...numbers) => numbers.every(n => n > 0))(5,6,7);
+((...mixed) => mixed.every(n => !!n))(5,'oops','oh no');
+((...noNumbers) => noNumbers.some(n => n > 0))();
+((first, ...rest) => first ? [] : rest.map(n => n > 0))(8,9,10);
+// destructuring parameters (with defaults too!)
+(({ q }) => q)({ q : 13 });
+(({ p = 14 }) => p)({ p : 15 });
+(({ r = 17 } = { r: 18 }) => r)({r : 19});
+(({ u = 22 } = { u: 23 }) => u)();
+// contextually typed parameters.
+let twelve = (f => f(12))(i => i);
+let eleven = (o => o.a(11))({ a: function(n) { return n; } });
+// missing arguments
+(function(x, undefined) { return x; })(42);
+((x, y, z) => 42)();
+
+
+//// [contextuallyTypedIifeStrict.js]
+// arrow
+(function (jake) { })("build");
+// function expression
+(function (cats) { })("lol");
+// Lots of Irritating Superfluous Parentheses
+(function (x) { }("!"));
+((((function (y) { }))))("-");
+// multiple arguments
+(function (a, b, c) { })("foo", 101, false);
+// default parameters
+(function (m) {
+    if (m === void 0) { m = 10; }
+    return m + 1;
+})(12);
+(function (n) {
+    if (n === void 0) { n = 10; }
+    return n + 1;
+})();
+// optional parameters
+(function (j) { return j + 1; })(12);
+(function (k) { return k + 1; })();
+(function (l, o) { return l + o; })(12); // o should be any
+// rest parameters
+(function () {
+    var numbers = [];
+    for (var _i = 0; _i < arguments.length; _i++) {
+        numbers[_i] = arguments[_i];
+    }
+    return numbers.every(function (n) { return n > 0; });
+})(5, 6, 7);
+(function () {
+    var mixed = [];
+    for (var _i = 0; _i < arguments.length; _i++) {
+        mixed[_i] = arguments[_i];
+    }
+    return mixed.every(function (n) { return !!n; });
+})(5, 'oops', 'oh no');
+(function () {
+    var noNumbers = [];
+    for (var _i = 0; _i < arguments.length; _i++) {
+        noNumbers[_i] = arguments[_i];
+    }
+    return noNumbers.some(function (n) { return n > 0; });
+})();
+(function (first) {
+    var rest = [];
+    for (var _i = 1; _i < arguments.length; _i++) {
+        rest[_i - 1] = arguments[_i];
+    }
+    return first ? [] : rest.map(function (n) { return n > 0; });
+})(8, 9, 10);
+// destructuring parameters (with defaults too!)
+(function (_a) {
+    var q = _a.q;
+    return q;
+})({ q: 13 });
+(function (_a) {
+    var _b = _a.p, p = _b === void 0 ? 14 : _b;
+    return p;
+})({ p: 15 });
+(function (_a) {
+    var _b = (_a === void 0 ? { r: 18 } : _a).r, r = _b === void 0 ? 17 : _b;
+    return r;
+})({ r: 19 });
+(function (_a) {
+    var _b = (_a === void 0 ? { u: 23 } : _a).u, u = _b === void 0 ? 22 : _b;
+    return u;
+})();
+// contextually typed parameters.
+var twelve = (function (f) { return f(12); })(function (i) { return i; });
+var eleven = (function (o) { return o.a(11); })({ a: function (n) { return n; } });
+// missing arguments
+(function (x, undefined) { return x; })(42);
+(function (x, y, z) { return 42; })();

tests/baselines/reference/contextuallyTypedIifeStrict.symbols

@@ -0,0 +1,132 @@
+=== tests/cases/conformance/expressions/functions/contextuallyTypedIifeStrict.ts ===
+// arrow
+(jake => { })("build");
+>jake : Symbol(jake, Decl(contextuallyTypedIifeStrict.ts, 1, 1))
+
+// function expression
+(function (cats) { })("lol");
+>cats : Symbol(cats, Decl(contextuallyTypedIifeStrict.ts, 3, 11))
+
+// Lots of Irritating Superfluous Parentheses
+(function (x) { } ("!"));
+>x : Symbol(x, Decl(contextuallyTypedIifeStrict.ts, 5, 11))
+
+((((function (y) { }))))("-");
+>y : Symbol(y, Decl(contextuallyTypedIifeStrict.ts, 6, 14))
+
+// multiple arguments
+((a, b, c) => { })("foo", 101, false);
+>a : Symbol(a, Decl(contextuallyTypedIifeStrict.ts, 8, 2))
+>b : Symbol(b, Decl(contextuallyTypedIifeStrict.ts, 8, 4))
+>c : Symbol(c, Decl(contextuallyTypedIifeStrict.ts, 8, 7))
+
+// default parameters
+((m = 10) => m + 1)(12);
+>m : Symbol(m, Decl(contextuallyTypedIifeStrict.ts, 10, 2))
+>m : Symbol(m, Decl(contextuallyTypedIifeStrict.ts, 10, 2))
+
+((n = 10) => n + 1)();
+>n : Symbol(n, Decl(contextuallyTypedIifeStrict.ts, 11, 2))
+>n : Symbol(n, Decl(contextuallyTypedIifeStrict.ts, 11, 2))
+
+// optional parameters
+((j?) => j + 1)(12);
+>j : Symbol(j, Decl(contextuallyTypedIifeStrict.ts, 13, 2))
+>j : Symbol(j, Decl(contextuallyTypedIifeStrict.ts, 13, 2))
+
+((k?) => k + 1)();
+>k : Symbol(k, Decl(contextuallyTypedIifeStrict.ts, 14, 2))
+>k : Symbol(k, Decl(contextuallyTypedIifeStrict.ts, 14, 2))
+
+((l, o?) => l + o)(12); // o should be any
+>l : Symbol(l, Decl(contextuallyTypedIifeStrict.ts, 15, 2))
+>o : Symbol(o, Decl(contextuallyTypedIifeStrict.ts, 15, 4))
+>l : Symbol(l, Decl(contextuallyTypedIifeStrict.ts, 15, 2))
+>o : Symbol(o, Decl(contextuallyTypedIifeStrict.ts, 15, 4))
+
+// rest parameters
+((...numbers) => numbers.every(n => n > 0))(5,6,7);
+>numbers : Symbol(numbers, Decl(contextuallyTypedIifeStrict.ts, 17, 2))
+>numbers.every : Symbol(Array.every, Decl(lib.d.ts, --, --))
+>numbers : Symbol(numbers, Decl(contextuallyTypedIifeStrict.ts, 17, 2))
+>every : Symbol(Array.every, Decl(lib.d.ts, --, --))
+>n : Symbol(n, Decl(contextuallyTypedIifeStrict.ts, 17, 31))
+>n : Symbol(n, Decl(contextuallyTypedIifeStrict.ts, 17, 31))
+
+((...mixed) => mixed.every(n => !!n))(5,'oops','oh no');
+>mixed : Symbol(mixed, Decl(contextuallyTypedIifeStrict.ts, 18, 2))
+>mixed.every : Symbol(Array.every, Decl(lib.d.ts, --, --))
+>mixed : Symbol(mixed, Decl(contextuallyTypedIifeStrict.ts, 18, 2))
+>every : Symbol(Array.every, Decl(lib.d.ts, --, --))
+>n : Symbol(n, Decl(contextuallyTypedIifeStrict.ts, 18, 27))
+>n : Symbol(n, Decl(contextuallyTypedIifeStrict.ts, 18, 27))
+
+((...noNumbers) => noNumbers.some(n => n > 0))();
+>noNumbers : Symbol(noNumbers, Decl(contextuallyTypedIifeStrict.ts, 19, 2))
+>noNumbers.some : Symbol(Array.some, Decl(lib.d.ts, --, --))
+>noNumbers : Symbol(noNumbers, Decl(contextuallyTypedIifeStrict.ts, 19, 2))
+>some : Symbol(Array.some, Decl(lib.d.ts, --, --))
+>n : Symbol(n, Decl(contextuallyTypedIifeStrict.ts, 19, 34))
+>n : Symbol(n, Decl(contextuallyTypedIifeStrict.ts, 19, 34))
+
+((first, ...rest) => first ? [] : rest.map(n => n > 0))(8,9,10);
+>first : Symbol(first, Decl(contextuallyTypedIifeStrict.ts, 20, 2))
+>rest : Symbol(rest, Decl(contextuallyTypedIifeStrict.ts, 20, 8))
+>first : Symbol(first, Decl(contextuallyTypedIifeStrict.ts, 20, 2))
+>rest.map : Symbol(Array.map, Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --))
+>rest : Symbol(rest, Decl(contextuallyTypedIifeStrict.ts, 20, 8))
+>map : Symbol(Array.map, Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --))
+>n : Symbol(n, Decl(contextuallyTypedIifeStrict.ts, 20, 43))
+>n : Symbol(n, Decl(contextuallyTypedIifeStrict.ts, 20, 43))
+
+// destructuring parameters (with defaults too!)
+(({ q }) => q)({ q : 13 });
+>q : Symbol(q, Decl(contextuallyTypedIifeStrict.ts, 22, 3))
+>q : Symbol(q, Decl(contextuallyTypedIifeStrict.ts, 22, 3))
+>q : Symbol(q, Decl(contextuallyTypedIifeStrict.ts, 22, 16))
+
+(({ p = 14 }) => p)({ p : 15 });
+>p : Symbol(p, Decl(contextuallyTypedIifeStrict.ts, 23, 3))
+>p : Symbol(p, Decl(contextuallyTypedIifeStrict.ts, 23, 3))
+>p : Symbol(p, Decl(contextuallyTypedIifeStrict.ts, 23, 21))
+
+(({ r = 17 } = { r: 18 }) => r)({r : 19});
+>r : Symbol(r, Decl(contextuallyTypedIifeStrict.ts, 24, 3))
+>r : Symbol(r, Decl(contextuallyTypedIifeStrict.ts, 24, 16))
+>r : Symbol(r, Decl(contextuallyTypedIifeStrict.ts, 24, 3))
+>r : Symbol(r, Decl(contextuallyTypedIifeStrict.ts, 24, 33))
+
+(({ u = 22 } = { u: 23 }) => u)();
+>u : Symbol(u, Decl(contextuallyTypedIifeStrict.ts, 25, 3))
+>u : Symbol(u, Decl(contextuallyTypedIifeStrict.ts, 25, 16))
+>u : Symbol(u, Decl(contextuallyTypedIifeStrict.ts, 25, 3))
+
+// contextually typed parameters.
+let twelve = (f => f(12))(i => i);
+>twelve : Symbol(twelve, Decl(contextuallyTypedIifeStrict.ts, 27, 3))
+>f : Symbol(f, Decl(contextuallyTypedIifeStrict.ts, 27, 14))
+>f : Symbol(f, Decl(contextuallyTypedIifeStrict.ts, 27, 14))
+>i : Symbol(i, Decl(contextuallyTypedIifeStrict.ts, 27, 26))
+>i : Symbol(i, Decl(contextuallyTypedIifeStrict.ts, 27, 26))
+
+let eleven = (o => o.a(11))({ a: function(n) { return n; } });
+>eleven : Symbol(eleven, Decl(contextuallyTypedIifeStrict.ts, 28, 3))
+>o : Symbol(o, Decl(contextuallyTypedIifeStrict.ts, 28, 14))
+>o.a : Symbol(a, Decl(contextuallyTypedIifeStrict.ts, 28, 29))
+>o : Symbol(o, Decl(contextuallyTypedIifeStrict.ts, 28, 14))
+>a : Symbol(a, Decl(contextuallyTypedIifeStrict.ts, 28, 29))
+>a : Symbol(a, Decl(contextuallyTypedIifeStrict.ts, 28, 29))
+>n : Symbol(n, Decl(contextuallyTypedIifeStrict.ts, 28, 42))
+>n : Symbol(n, Decl(contextuallyTypedIifeStrict.ts, 28, 42))
+
+// missing arguments
+(function(x, undefined) { return x; })(42);
+>x : Symbol(x, Decl(contextuallyTypedIifeStrict.ts, 30, 10))
+>undefined : Symbol(undefined, Decl(contextuallyTypedIifeStrict.ts, 30, 12))
+>x : Symbol(x, Decl(contextuallyTypedIifeStrict.ts, 30, 10))
+
+((x, y, z) => 42)();
+>x : Symbol(x, Decl(contextuallyTypedIifeStrict.ts, 31, 2))
+>y : Symbol(y, Decl(contextuallyTypedIifeStrict.ts, 31, 4))
+>z : Symbol(z, Decl(contextuallyTypedIifeStrict.ts, 31, 7))
+

tests/baselines/reference/contextuallyTypedIifeStrict.types

@@ -0,0 +1,271 @@
+=== tests/cases/conformance/expressions/functions/contextuallyTypedIifeStrict.ts ===
+// arrow
+(jake => { })("build");
+>(jake => { })("build") : void
+>(jake => { }) : (jake: string) => void
+>jake => { } : (jake: string) => void
+>jake : string
+>"build" : "build"
+
+// function expression
+(function (cats) { })("lol");
+>(function (cats) { })("lol") : void
+>(function (cats) { }) : (cats: string) => void
+>function (cats) { } : (cats: string) => void
+>cats : string
+>"lol" : "lol"
+
+// Lots of Irritating Superfluous Parentheses
+(function (x) { } ("!"));
+>(function (x) { } ("!")) : void
+>function (x) { } ("!") : void
+>function (x) { } : (x: string) => void
+>x : string
+>"!" : "!"
+
+((((function (y) { }))))("-");
+>((((function (y) { }))))("-") : void
+>((((function (y) { })))) : (y: string) => void
+>(((function (y) { }))) : (y: string) => void
+>((function (y) { })) : (y: string) => void
+>(function (y) { }) : (y: string) => void
+>function (y) { } : (y: string) => void
+>y : string
+>"-" : "-"
+
+// multiple arguments
+((a, b, c) => { })("foo", 101, false);
+>((a, b, c) => { })("foo", 101, false) : void
+>((a, b, c) => { }) : (a: string, b: number, c: boolean) => void
+>(a, b, c) => { } : (a: string, b: number, c: boolean) => void
+>a : string
+>b : number
+>c : boolean
+>"foo" : "foo"
+>101 : 101
+>false : false
+
+// default parameters
+((m = 10) => m + 1)(12);
+>((m = 10) => m + 1)(12) : number
+>((m = 10) => m + 1) : (m?: number) => number
+>(m = 10) => m + 1 : (m?: number) => number
+>m : number
+>10 : 10
+>m + 1 : number
+>m : number
+>1 : 1
+>12 : 12
+
+((n = 10) => n + 1)();
+>((n = 10) => n + 1)() : number
+>((n = 10) => n + 1) : (n?: number) => number
+>(n = 10) => n + 1 : (n?: number) => number
+>n : number
+>10 : 10
+>n + 1 : number
+>n : number
+>1 : 1
+
+// optional parameters
+((j?) => j + 1)(12);
+>((j?) => j + 1)(12) : number
+>((j?) => j + 1) : (j?: number | undefined) => number
+>(j?) => j + 1 : (j?: number | undefined) => number
+>j : number | undefined
+>j + 1 : number
+>j : number | undefined
+>1 : 1
+>12 : 12
+
+((k?) => k + 1)();
+>((k?) => k + 1)() : number
+>((k?) => k + 1) : (k?: undefined) => number
+>(k?) => k + 1 : (k?: undefined) => number
+>k : undefined
+>k + 1 : number
+>k : undefined
+>1 : 1
+
+((l, o?) => l + o)(12); // o should be any
+>((l, o?) => l + o)(12) : number
+>((l, o?) => l + o) : (l: number, o?: undefined) => number
+>(l, o?) => l + o : (l: number, o?: undefined) => number
+>l : number
+>o : undefined
+>l + o : number
+>l : number
+>o : undefined
+>12 : 12
+
+// rest parameters
+((...numbers) => numbers.every(n => n > 0))(5,6,7);
+>((...numbers) => numbers.every(n => n > 0))(5,6,7) : boolean
+>((...numbers) => numbers.every(n => n > 0)) : (...numbers: number[]) => boolean
+>(...numbers) => numbers.every(n => n > 0) : (...numbers: number[]) => boolean
+>numbers : number[]
+>numbers.every(n => n > 0) : boolean
+>numbers.every : (callbackfn: (value: number, index: number, array: number[]) => boolean, thisArg?: any) => boolean
+>numbers : number[]
+>every : (callbackfn: (value: number, index: number, array: number[]) => boolean, thisArg?: any) => boolean
+>n => n > 0 : (n: number) => boolean
+>n : number
+>n > 0 : boolean
+>n : number
+>0 : 0
+>5 : 5
+>6 : 6
+>7 : 7
+
+((...mixed) => mixed.every(n => !!n))(5,'oops','oh no');
+>((...mixed) => mixed.every(n => !!n))(5,'oops','oh no') : boolean
+>((...mixed) => mixed.every(n => !!n)) : (...mixed: (string | number)[]) => boolean
+>(...mixed) => mixed.every(n => !!n) : (...mixed: (string | number)[]) => boolean
+>mixed : (string | number)[]
+>mixed.every(n => !!n) : boolean
+>mixed.every : (callbackfn: (value: string | number, index: number, array: (string | number)[]) => boolean, thisArg?: any) => boolean
+>mixed : (string | number)[]
+>every : (callbackfn: (value: string | number, index: number, array: (string | number)[]) => boolean, thisArg?: any) => boolean
+>n => !!n : (n: string | number) => boolean
+>n : string | number
+>!!n : boolean
+>!n : boolean
+>n : string | number
+>5 : 5
+>'oops' : "oops"
+>'oh no' : "oh no"
+
+((...noNumbers) => noNumbers.some(n => n > 0))();
+>((...noNumbers) => noNumbers.some(n => n > 0))() : boolean
+>((...noNumbers) => noNumbers.some(n => n > 0)) : (...noNumbers: any[]) => boolean
+>(...noNumbers) => noNumbers.some(n => n > 0) : (...noNumbers: any[]) => boolean
+>noNumbers : any[]
+>noNumbers.some(n => n > 0) : boolean
+>noNumbers.some : (callbackfn: (value: any, index: number, array: any[]) => boolean, thisArg?: any) => boolean
+>noNumbers : any[]
+>some : (callbackfn: (value: any, index: number, array: any[]) => boolean, thisArg?: any) => boolean
+>n => n > 0 : (n: any) => boolean
+>n : any
+>n > 0 : boolean
+>n : any
+>0 : 0
+
+((first, ...rest) => first ? [] : rest.map(n => n > 0))(8,9,10);
+>((first, ...rest) => first ? [] : rest.map(n => n > 0))(8,9,10) : boolean[]
+>((first, ...rest) => first ? [] : rest.map(n => n > 0)) : (first: number, ...rest: number[]) => boolean[]
+>(first, ...rest) => first ? [] : rest.map(n => n > 0) : (first: number, ...rest: number[]) => boolean[]
+>first : number
+>rest : number[]
+>first ? [] : rest.map(n => n > 0) : boolean[]
+>first : number
+>[] : never[]
+>rest.map(n => n > 0) : boolean[]
+>rest.map : { <U>(this: [number, number, number, number, number], callbackfn: (value: number, index: number, array: number[]) => U, thisArg?: any): [U, U, U, U, U]; <U>(this: [number, number, number, number], callbackfn: (value: number, index: number, array: number[]) => U, thisArg?: any): [U, U, U, U]; <U>(this: [number, number, number], callbackfn: (value: number, index: number, array: number[]) => U, thisArg?: any): [U, U, U]; <U>(this: [number, number], callbackfn: (value: number, index: number, array: number[]) => U, thisArg?: any): [U, U]; <U>(callbackfn: (value: number, index: number, array: number[]) => U, thisArg?: any): U[]; }
+>rest : number[]
+>map : { <U>(this: [number, number, number, number, number], callbackfn: (value: number, index: number, array: number[]) => U, thisArg?: any): [U, U, U, U, U]; <U>(this: [number, number, number, number], callbackfn: (value: number, index: number, array: number[]) => U, thisArg?: any): [U, U, U, U]; <U>(this: [number, number, number], callbackfn: (value: number, index: number, array: number[]) => U, thisArg?: any): [U, U, U]; <U>(this: [number, number], callbackfn: (value: number, index: number, array: number[]) => U, thisArg?: any): [U, U]; <U>(callbackfn: (value: number, index: number, array: number[]) => U, thisArg?: any): U[]; }
+>n => n > 0 : (n: number) => boolean
+>n : number
+>n > 0 : boolean
+>n : number
+>0 : 0
+>8 : 8
+>9 : 9
+>10 : 10
+
+// destructuring parameters (with defaults too!)
+(({ q }) => q)({ q : 13 });
+>(({ q }) => q)({ q : 13 }) : number
+>(({ q }) => q) : ({q}: { q: number; }) => number
+>({ q }) => q : ({q}: { q: number; }) => number
+>q : number
+>q : number
+>{ q : 13 } : { q: number; }
+>q : number
+>13 : 13
+
+(({ p = 14 }) => p)({ p : 15 });
+>(({ p = 14 }) => p)({ p : 15 }) : number
+>(({ p = 14 }) => p) : ({p}: { p: number; }) => number
+>({ p = 14 }) => p : ({p}: { p: number; }) => number
+>p : number
+>14 : 14
+>p : number
+>{ p : 15 } : { p: number; }
+>p : number
+>15 : 15
+
+(({ r = 17 } = { r: 18 }) => r)({r : 19});
+>(({ r = 17 } = { r: 18 }) => r)({r : 19}) : number
+>(({ r = 17 } = { r: 18 }) => r) : ({r}?: { r: number; }) => number
+>({ r = 17 } = { r: 18 }) => r : ({r}?: { r: number; }) => number
+>r : number
+>17 : 17
+>{ r: 18 } : { r: number; }
+>r : number
+>18 : 18
+>r : number
+>{r : 19} : { r: number; }
+>r : number
+>19 : 19
+
+(({ u = 22 } = { u: 23 }) => u)();
+>(({ u = 22 } = { u: 23 }) => u)() : number
+>(({ u = 22 } = { u: 23 }) => u) : ({u}?: { u?: number; }) => number
+>({ u = 22 } = { u: 23 }) => u : ({u}?: { u?: number; }) => number
+>u : number
+>22 : 22
+>{ u: 23 } : { u?: number; }
+>u : number
+>23 : 23
+>u : number
+
+// contextually typed parameters.
+let twelve = (f => f(12))(i => i);
+>twelve : any
+>(f => f(12))(i => i) : any
+>(f => f(12)) : (f: (i: any) => any) => any
+>f => f(12) : (f: (i: any) => any) => any
+>f : (i: any) => any
+>f(12) : any
+>f : (i: any) => any
+>12 : 12
+>i => i : (i: any) => any
+>i : any
+>i : any
+
+let eleven = (o => o.a(11))({ a: function(n) { return n; } });
+>eleven : any
+>(o => o.a(11))({ a: function(n) { return n; } }) : any
+>(o => o.a(11)) : (o: { a: (n: any) => any; }) => any
+>o => o.a(11) : (o: { a: (n: any) => any; }) => any
+>o : { a: (n: any) => any; }
+>o.a(11) : any
+>o.a : (n: any) => any
+>o : { a: (n: any) => any; }
+>a : (n: any) => any
+>11 : 11
+>{ a: function(n) { return n; } } : { a: (n: any) => any; }
+>a : (n: any) => any
+>function(n) { return n; } : (n: any) => any
+>n : any
+>n : any
+
+// missing arguments
+(function(x, undefined) { return x; })(42);
+>(function(x, undefined) { return x; })(42) : number
+>(function(x, undefined) { return x; }) : (x: number, undefined: undefined) => number
+>function(x, undefined) { return x; } : (x: number, undefined: undefined) => number
+>x : number
+>undefined : undefined
+>x : number
+>42 : 42
+
+((x, y, z) => 42)();
+>((x, y, z) => 42)() : number
+>((x, y, z) => 42) : (x: undefined, y: undefined, z: undefined) => number
+>(x, y, z) => 42 : (x: undefined, y: undefined, z: undefined) => number
+>x : undefined
+>y : undefined
+>z : undefined
+>42 : 42
+

tests/cases/conformance/expressions/functions/contextuallyTypedIife.ts

@@ -27,3 +27,6 @@
 // contextually typed parameters.
 let twelve = (f => f(12))(i => i);
 let eleven = (o => o.a(11))({ a: function(n) { return n; } });
+// missing arguments
+(function(x, undefined) { return x; })(42);
+((x, y, z) => 42)();

tests/cases/conformance/expressions/functions/contextuallyTypedIifeStrict.ts

@@ -0,0 +1,33 @@
+// @strictNullChecks: true
+// arrow
+(jake => { })("build");
+// function expression
+(function (cats) { })("lol");
+// Lots of Irritating Superfluous Parentheses
+(function (x) { } ("!"));
+((((function (y) { }))))("-");
+// multiple arguments
+((a, b, c) => { })("foo", 101, false);
+// default parameters
+((m = 10) => m + 1)(12);
+((n = 10) => n + 1)();
+// optional parameters
+((j?) => j + 1)(12);
+((k?) => k + 1)();
+((l, o?) => l + o)(12); // o should be any
+// rest parameters
+((...numbers) => numbers.every(n => n > 0))(5,6,7);
+((...mixed) => mixed.every(n => !!n))(5,'oops','oh no');
+((...noNumbers) => noNumbers.some(n => n > 0))();
+((first, ...rest) => first ? [] : rest.map(n => n > 0))(8,9,10);
+// destructuring parameters (with defaults too!)
+(({ q }) => q)({ q : 13 });
+(({ p = 14 }) => p)({ p : 15 });
+(({ r = 17 } = { r: 18 }) => r)({r : 19});
+(({ u = 22 } = { u: 23 }) => u)();
+// contextually typed parameters.
+let twelve = (f => f(12))(i => i);
+let eleven = (o => o.a(11))({ a: function(n) { return n; } });
+// missing arguments
+(function(x, undefined) { return x; })(42);
+((x, y, z) => 42)();