Now that we speculate, we can and should reset argCheckMode for every overload we check

Author: weswigham

src/compiler/checker.ts

@@ -34964,7 +34964,6 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
         // For a decorator, no arguments are susceptible to contextual typing due to the fact
         // decorators are applied to a declaration by the emitter, and not to an expression.
         const isSingleNonGenericCandidate = candidates.length === 1 && !candidates[0].typeParameters;
-        let argCheckMode = !isDecorator && !isSingleNonGenericCandidate && some(args, isContextSensitive) ? CheckMode.SkipContextSensitive : CheckMode.Normal;
 
         // The following variables are captured and modified by calls to chooseOverload.
         // If overload resolution or type argument inference fails, we want to report the
@@ -35173,12 +35172,14 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
                 return candidate;
             }
 
+            const initialCheckMode = !isDecorator && !isSingleNonGenericCandidate && some(args, isContextSensitive) ? CheckMode.SkipContextSensitive : CheckMode.Normal;
             for (let candidateIndex = 0; candidateIndex < candidates.length; candidateIndex++) {
                 const candidate = candidates[candidateIndex];
                 if (!hasCorrectTypeArgumentArity(candidate, typeArguments) || !hasCorrectArity(node, args, candidate, signatureHelpTrailingComma)) {
                     continue;
                 }
                 const result = speculate(() => {
+                    let argCheckMode = initialCheckMode;
                     let checkCandidate: Signature;
                     let inferenceContext: InferenceContext | undefined;
 

tests/baselines/reference/contextuallyTypedStringLiteralsInJsxAttributes02.errors.txt

@@ -10,8 +10,7 @@ file.tsx(28,13): error TS2769: No overload matches this call.
     Type '{ onClick: (k: "left" | "right") => void; extra: true; }' is not assignable to type 'IntrinsicAttributes & ButtonProps'.
       Property 'extra' does not exist on type 'IntrinsicAttributes & ButtonProps'.
   Overload 2 of 2, '(linkProps: LinkProps): Element', gave the following error.
-    Type '{ onClick: (k: any) => void; extra: true; }' is not assignable to type 'IntrinsicAttributes & LinkProps'.
-      Property 'onClick' does not exist on type 'IntrinsicAttributes & LinkProps'.
+    Property 'goTo' is missing in type '{ onClick: {}; extra: true; }' but required in type 'LinkProps'.
 file.tsx(29,43): error TS2769: No overload matches this call.
   Overload 1 of 2, '(buttonProps: ButtonProps): Element', gave the following error.
     Type '{ extra: true; goTo: string; }' is not assignable to type 'IntrinsicAttributes & ButtonProps'.
@@ -75,8 +74,8 @@ file.tsx(36,44): error TS2322: Type '{ extra: true; goTo: "home"; }' is not assi
 !!! error TS2769:     Type '{ onClick: (k: "left" | "right") => void; extra: true; }' is not assignable to type 'IntrinsicAttributes & ButtonProps'.
 !!! error TS2769:       Property 'extra' does not exist on type 'IntrinsicAttributes & ButtonProps'.
 !!! error TS2769:   Overload 2 of 2, '(linkProps: LinkProps): Element', gave the following error.
-!!! error TS2769:     Type '{ onClick: (k: any) => void; extra: true; }' is not assignable to type 'IntrinsicAttributes & LinkProps'.
-!!! error TS2769:       Property 'onClick' does not exist on type 'IntrinsicAttributes & LinkProps'.
+!!! error TS2769:     Property 'goTo' is missing in type '{ onClick: {}; extra: true; }' but required in type 'LinkProps'.
+!!! related TS2728 file.tsx:13:5: 'goTo' is declared here.
     const b3 = <MainButton {...{goTo:"home"}} extra />;  // goTo has type"home" | "contact"
                                               ~~~~~
 !!! error TS2769: No overload matches this call.

tests/baselines/reference/destructuringTuple.errors.txt

@@ -1,8 +1,14 @@
-destructuringTuple.ts(11,7): error TS2461: Type 'unknown' is not an array type.
-destructuringTuple.ts(11,48): error TS18046: 'accu' is of type 'unknown'.
+destructuringTuple.ts(11,7): error TS2461: Type 'number' is not an array type.
+destructuringTuple.ts(11,27): error TS2769: No overload matches this call.
+  Overload 1 of 3, '(callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number, initialValue: number): number', gave the following error.
+    Argument of type 'never[]' is not assignable to parameter of type 'number'.
+  Overload 2 of 3, '(callbackfn: (previousValue: [], currentValue: number, currentIndex: number, array: number[]) => [], initialValue: []): []', gave the following error.
+    Type 'never[]' is not assignable to type '[]'.
+      Target allows only 0 element(s) but source may have more.
+destructuringTuple.ts(11,53): error TS2339: Property 'concat' does not exist on type 'number'.
 
 
-==== destructuringTuple.ts (2 errors) ====
+==== destructuringTuple.ts (3 errors) ====
     declare var tuple: [boolean, number, ...string[]];
 
     const [a, b, c, ...rest] = tuple;
@@ -15,9 +21,17 @@ destructuringTuple.ts(11,48): error TS18046: 'accu' is of type 'unknown'.
 
     const [oops1] = [1, 2, 3].reduce((accu, el) => accu.concat(el), []);
           ~~~~~~~
-!!! error TS2461: Type 'unknown' is not an array type.
-                                                   ~~~~
-!!! error TS18046: 'accu' is of type 'unknown'.
+!!! error TS2461: Type 'number' is not an array type.
+                              ~~~~~~
+!!! error TS2769: No overload matches this call.
+!!! error TS2769:   Overload 1 of 3, '(callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number, initialValue: number): number', gave the following error.
+!!! error TS2769:     Argument of type 'never[]' is not assignable to parameter of type 'number'.
+!!! error TS2769:   Overload 2 of 3, '(callbackfn: (previousValue: [], currentValue: number, currentIndex: number, array: number[]) => [], initialValue: []): []', gave the following error.
+!!! error TS2769:     Type 'never[]' is not assignable to type '[]'.
+!!! error TS2769:       Target allows only 0 element(s) but source may have more.
+!!! related TS6502 lib.es5.d.ts:--:--: The expected type comes from the return type of this signature.
+                                                        ~~~~~~
+!!! error TS2339: Property 'concat' does not exist on type 'number'.
 
     const [oops2] = [1, 2, 3].reduce((acc: number[], e) => acc.concat(e), []);
 

tests/baselines/reference/destructuringTuple.types

@@ -26,19 +26,19 @@ declare var receiver: typeof tuple;
 
 const [oops1] = [1, 2, 3].reduce((accu, el) => accu.concat(el), []);
 >oops1 : any
->[1, 2, 3].reduce((accu, el) => accu.concat(el), []) : unknown
+>[1, 2, 3].reduce((accu, el) => accu.concat(el), []) : number
 >[1, 2, 3].reduce : { (callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number): number; (callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number, initialValue: number): number; <U>(callbackfn: (previousValue: U, currentValue: number, currentIndex: number, array: number[]) => U, initialValue: U): U; }
 >[1, 2, 3] : number[]
 >1 : 1
 >2 : 2
 >3 : 3
 >reduce : { (callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number): number; (callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number, initialValue: number): number; <U>(callbackfn: (previousValue: U, currentValue: number, currentIndex: number, array: number[]) => U, initialValue: U): U; }
->(accu, el) => accu.concat(el) : (accu: unknown, el: number) => any
->accu : unknown
+>(accu, el) => accu.concat(el) : (accu: number, el: number) => any
+>accu : number
 >el : number
 >accu.concat(el) : any
 >accu.concat : any
->accu : unknown
+>accu : number
 >concat : any
 >el : number
 >[] : never[]

tests/baselines/reference/functionOverloadInformsPriorArgumentType.js

@@ -0,0 +1,38 @@
+//// [tests/cases/compiler/functionOverloadInformsPriorArgumentType.ts] ////
+
+//// [functionOverloadInformsPriorArgumentType.ts]
+enum ModifierFlags {
+    None = 0,
+    In = 1,
+    Out = 2,
+    Const = 4,
+    Other = 8,
+}
+
+interface Declaration {
+    modifierFlags: ModifierFlags;
+}
+
+declare function getEffectiveModifierFlags(d: Declaration): ModifierFlags;
+
+declare function reduceLeft<T, U>(array: readonly T[] | undefined, f: (memo: U, value: T, i: number) => U, initial: U, start?: number, count?: number): U;
+// only has an issue when the 2nd overload is present, even though it has an arity mismatch
+declare function reduceLeft<T>(array: readonly T[], f: (memo: T, value: T, i: number) => T): T | undefined;
+
+function getTypeParameterModifiers(declarations: Declaration[]): ModifierFlags {
+    return reduceLeft(declarations, (modifiers, d) => modifiers | getEffectiveModifierFlags(d), ModifierFlags.None) & (ModifierFlags.In | ModifierFlags.Out | ModifierFlags.Const);
+}
+
+//// [functionOverloadInformsPriorArgumentType.js]
+"use strict";
+var ModifierFlags;
+(function (ModifierFlags) {
+    ModifierFlags[ModifierFlags["None"] = 0] = "None";
+    ModifierFlags[ModifierFlags["In"] = 1] = "In";
+    ModifierFlags[ModifierFlags["Out"] = 2] = "Out";
+    ModifierFlags[ModifierFlags["Const"] = 4] = "Const";
+    ModifierFlags[ModifierFlags["Other"] = 8] = "Other";
+})(ModifierFlags || (ModifierFlags = {}));
+function getTypeParameterModifiers(declarations) {
+    return reduceLeft(declarations, function (modifiers, d) { return modifiers | getEffectiveModifierFlags(d); }, ModifierFlags.None) & (ModifierFlags.In | ModifierFlags.Out | ModifierFlags.Const);
+}

tests/baselines/reference/functionOverloadInformsPriorArgumentType.symbols

@@ -0,0 +1,97 @@
+//// [tests/cases/compiler/functionOverloadInformsPriorArgumentType.ts] ////
+
+=== functionOverloadInformsPriorArgumentType.ts ===
+enum ModifierFlags {
+>ModifierFlags : Symbol(ModifierFlags, Decl(functionOverloadInformsPriorArgumentType.ts, 0, 0))
+
+    None = 0,
+>None : Symbol(ModifierFlags.None, Decl(functionOverloadInformsPriorArgumentType.ts, 0, 20))
+
+    In = 1,
+>In : Symbol(ModifierFlags.In, Decl(functionOverloadInformsPriorArgumentType.ts, 1, 13))
+
+    Out = 2,
+>Out : Symbol(ModifierFlags.Out, Decl(functionOverloadInformsPriorArgumentType.ts, 2, 11))
+
+    Const = 4,
+>Const : Symbol(ModifierFlags.Const, Decl(functionOverloadInformsPriorArgumentType.ts, 3, 12))
+
+    Other = 8,
+>Other : Symbol(ModifierFlags.Other, Decl(functionOverloadInformsPriorArgumentType.ts, 4, 14))
+}
+
+interface Declaration {
+>Declaration : Symbol(Declaration, Decl(functionOverloadInformsPriorArgumentType.ts, 6, 1))
+
+    modifierFlags: ModifierFlags;
+>modifierFlags : Symbol(Declaration.modifierFlags, Decl(functionOverloadInformsPriorArgumentType.ts, 8, 23))
+>ModifierFlags : Symbol(ModifierFlags, Decl(functionOverloadInformsPriorArgumentType.ts, 0, 0))
+}
+
+declare function getEffectiveModifierFlags(d: Declaration): ModifierFlags;
+>getEffectiveModifierFlags : Symbol(getEffectiveModifierFlags, Decl(functionOverloadInformsPriorArgumentType.ts, 10, 1))
+>d : Symbol(d, Decl(functionOverloadInformsPriorArgumentType.ts, 12, 43))
+>Declaration : Symbol(Declaration, Decl(functionOverloadInformsPriorArgumentType.ts, 6, 1))
+>ModifierFlags : Symbol(ModifierFlags, Decl(functionOverloadInformsPriorArgumentType.ts, 0, 0))
+
+declare function reduceLeft<T, U>(array: readonly T[] | undefined, f: (memo: U, value: T, i: number) => U, initial: U, start?: number, count?: number): U;
+>reduceLeft : Symbol(reduceLeft, Decl(functionOverloadInformsPriorArgumentType.ts, 12, 74), Decl(functionOverloadInformsPriorArgumentType.ts, 14, 154))
+>T : Symbol(T, Decl(functionOverloadInformsPriorArgumentType.ts, 14, 28))
+>U : Symbol(U, Decl(functionOverloadInformsPriorArgumentType.ts, 14, 30))
+>array : Symbol(array, Decl(functionOverloadInformsPriorArgumentType.ts, 14, 34))
+>T : Symbol(T, Decl(functionOverloadInformsPriorArgumentType.ts, 14, 28))
+>f : Symbol(f, Decl(functionOverloadInformsPriorArgumentType.ts, 14, 66))
+>memo : Symbol(memo, Decl(functionOverloadInformsPriorArgumentType.ts, 14, 71))
+>U : Symbol(U, Decl(functionOverloadInformsPriorArgumentType.ts, 14, 30))
+>value : Symbol(value, Decl(functionOverloadInformsPriorArgumentType.ts, 14, 79))
+>T : Symbol(T, Decl(functionOverloadInformsPriorArgumentType.ts, 14, 28))
+>i : Symbol(i, Decl(functionOverloadInformsPriorArgumentType.ts, 14, 89))
+>U : Symbol(U, Decl(functionOverloadInformsPriorArgumentType.ts, 14, 30))
+>initial : Symbol(initial, Decl(functionOverloadInformsPriorArgumentType.ts, 14, 106))
+>U : Symbol(U, Decl(functionOverloadInformsPriorArgumentType.ts, 14, 30))
+>start : Symbol(start, Decl(functionOverloadInformsPriorArgumentType.ts, 14, 118))
+>count : Symbol(count, Decl(functionOverloadInformsPriorArgumentType.ts, 14, 134))
+>U : Symbol(U, Decl(functionOverloadInformsPriorArgumentType.ts, 14, 30))
+
+// only has an issue when the 2nd overload is present, even though it has an arity mismatch
+declare function reduceLeft<T>(array: readonly T[], f: (memo: T, value: T, i: number) => T): T | undefined;
+>reduceLeft : Symbol(reduceLeft, Decl(functionOverloadInformsPriorArgumentType.ts, 12, 74), Decl(functionOverloadInformsPriorArgumentType.ts, 14, 154))
+>T : Symbol(T, Decl(functionOverloadInformsPriorArgumentType.ts, 16, 28))
+>array : Symbol(array, Decl(functionOverloadInformsPriorArgumentType.ts, 16, 31))
+>T : Symbol(T, Decl(functionOverloadInformsPriorArgumentType.ts, 16, 28))
+>f : Symbol(f, Decl(functionOverloadInformsPriorArgumentType.ts, 16, 51))
+>memo : Symbol(memo, Decl(functionOverloadInformsPriorArgumentType.ts, 16, 56))
+>T : Symbol(T, Decl(functionOverloadInformsPriorArgumentType.ts, 16, 28))
+>value : Symbol(value, Decl(functionOverloadInformsPriorArgumentType.ts, 16, 64))
+>T : Symbol(T, Decl(functionOverloadInformsPriorArgumentType.ts, 16, 28))
+>i : Symbol(i, Decl(functionOverloadInformsPriorArgumentType.ts, 16, 74))
+>T : Symbol(T, Decl(functionOverloadInformsPriorArgumentType.ts, 16, 28))
+>T : Symbol(T, Decl(functionOverloadInformsPriorArgumentType.ts, 16, 28))
+
+function getTypeParameterModifiers(declarations: Declaration[]): ModifierFlags {
+>getTypeParameterModifiers : Symbol(getTypeParameterModifiers, Decl(functionOverloadInformsPriorArgumentType.ts, 16, 107))
+>declarations : Symbol(declarations, Decl(functionOverloadInformsPriorArgumentType.ts, 18, 35))
+>Declaration : Symbol(Declaration, Decl(functionOverloadInformsPriorArgumentType.ts, 6, 1))
+>ModifierFlags : Symbol(ModifierFlags, Decl(functionOverloadInformsPriorArgumentType.ts, 0, 0))
+
+    return reduceLeft(declarations, (modifiers, d) => modifiers | getEffectiveModifierFlags(d), ModifierFlags.None) & (ModifierFlags.In | ModifierFlags.Out | ModifierFlags.Const);
+>reduceLeft : Symbol(reduceLeft, Decl(functionOverloadInformsPriorArgumentType.ts, 12, 74), Decl(functionOverloadInformsPriorArgumentType.ts, 14, 154))
+>declarations : Symbol(declarations, Decl(functionOverloadInformsPriorArgumentType.ts, 18, 35))
+>modifiers : Symbol(modifiers, Decl(functionOverloadInformsPriorArgumentType.ts, 19, 37))
+>d : Symbol(d, Decl(functionOverloadInformsPriorArgumentType.ts, 19, 47))
+>modifiers : Symbol(modifiers, Decl(functionOverloadInformsPriorArgumentType.ts, 19, 37))
+>getEffectiveModifierFlags : Symbol(getEffectiveModifierFlags, Decl(functionOverloadInformsPriorArgumentType.ts, 10, 1))
+>d : Symbol(d, Decl(functionOverloadInformsPriorArgumentType.ts, 19, 47))
+>ModifierFlags.None : Symbol(ModifierFlags.None, Decl(functionOverloadInformsPriorArgumentType.ts, 0, 20))
+>ModifierFlags : Symbol(ModifierFlags, Decl(functionOverloadInformsPriorArgumentType.ts, 0, 0))
+>None : Symbol(ModifierFlags.None, Decl(functionOverloadInformsPriorArgumentType.ts, 0, 20))
+>ModifierFlags.In : Symbol(ModifierFlags.In, Decl(functionOverloadInformsPriorArgumentType.ts, 1, 13))
+>ModifierFlags : Symbol(ModifierFlags, Decl(functionOverloadInformsPriorArgumentType.ts, 0, 0))
+>In : Symbol(ModifierFlags.In, Decl(functionOverloadInformsPriorArgumentType.ts, 1, 13))
+>ModifierFlags.Out : Symbol(ModifierFlags.Out, Decl(functionOverloadInformsPriorArgumentType.ts, 2, 11))
+>ModifierFlags : Symbol(ModifierFlags, Decl(functionOverloadInformsPriorArgumentType.ts, 0, 0))
+>Out : Symbol(ModifierFlags.Out, Decl(functionOverloadInformsPriorArgumentType.ts, 2, 11))
+>ModifierFlags.Const : Symbol(ModifierFlags.Const, Decl(functionOverloadInformsPriorArgumentType.ts, 3, 12))
+>ModifierFlags : Symbol(ModifierFlags, Decl(functionOverloadInformsPriorArgumentType.ts, 0, 0))
+>Const : Symbol(ModifierFlags.Const, Decl(functionOverloadInformsPriorArgumentType.ts, 3, 12))
+}