Make overload resolution more elaborate

src/compiler/core.ts

@@ -274,6 +274,12 @@ module ts {
         };
     }
 
+    export function concatenateDiagnosticMessageChains(headChain: DiagnosticMessageChain, tailChain: DiagnosticMessageChain): DiagnosticMessageChain {
+        Debug.assert(!headChain.next);
+        headChain.next = tailChain;
+        return headChain;
+    }
+
     export function flattenDiagnosticChain(file: SourceFile, start: number, length: number, diagnosticChain: DiagnosticMessageChain, newLine: string): Diagnostic {
         Debug.assert(start >= 0, "start must be non-negative, is " + start);
         Debug.assert(length >= 0, "length must be non-negative, is " + length);

src/compiler/diagnosticInformationMap.generated.ts

@@ -271,6 +271,9 @@ module ts {
         Left_hand_side_of_assignment_expression_cannot_be_a_constant: { code: 2450, category: DiagnosticCategory.Error, key: "Left-hand side of assignment expression cannot be a constant.", isEarly: true },
         Cannot_redeclare_block_scoped_variable_0: { code: 2451, category: DiagnosticCategory.Error, key: "Cannot redeclare block-scoped variable '{0}'.", isEarly: true },
         An_enum_member_cannot_have_a_numeric_name: { code: 2452, category: DiagnosticCategory.Error, key: "An enum member cannot have a numeric name." },
+        The_type_argument_for_type_parameter_0_cannot_be_inferred_from_the_usage_Consider_specifying_the_type_arguments_explicitly_Colon: { code: 2453, category: DiagnosticCategory.Error, key: "The type argument for type parameter '{0}' cannot be inferred from the usage. Consider specifying the type arguments explicitly:" },
+        Type_argument_candidate_1_is_not_a_valid_type_argument_because_it_is_not_a_supertype_of_candidate_0_Colon: { code: 2454, category: DiagnosticCategory.Error, key: "Type argument candidate '{1}' is not a valid type argument because it is not a supertype of candidate '{0}':" },
+        Type_argument_candidate_1_is_not_a_valid_type_argument_because_it_is_not_a_supertype_of_candidate_0: { code: 2455, category: DiagnosticCategory.Error, key: "Type argument candidate '{1}' is not a valid type argument because it is not a supertype of candidate '{0}'." },
         Import_declaration_0_is_using_private_name_1: { code: 4000, category: DiagnosticCategory.Error, key: "Import declaration '{0}' is using private name '{1}'." },
         Type_parameter_0_of_exported_class_has_or_is_using_name_1_from_private_module_2: { code: 4001, category: DiagnosticCategory.Error, key: "Type parameter '{0}' of exported class has or is using name '{1}' from private module '{2}'." },
         Type_parameter_0_of_exported_class_has_or_is_using_private_name_1: { code: 4002, category: DiagnosticCategory.Error, key: "Type parameter '{0}' of exported class has or is using private name '{1}'." },

src/compiler/diagnosticMessages.json

@@ -1080,6 +1080,18 @@
         "category": "Error",
         "code": 2452
     },
+    "The type argument for type parameter '{0}' cannot be inferred from the usage. Consider specifying the type arguments explicitly:": {
+        "category": "Error",
+        "code": 2453
+    },
+    "Type argument candidate '{1}' is not a valid type argument because it is not a supertype of candidate '{0}':": {
+        "category": "Error",
+        "code": 2454
+    },
+    "Type argument candidate '{1}' is not a valid type argument because it is not a supertype of candidate '{0}'.": {
+        "category": "Error",
+        "code": 2455
+    },
 
     "Import declaration '{0}' is using private name '{1}'.": {
         "category": "Error",

src/compiler/types.ts

@@ -1034,6 +1034,8 @@ module ts {
         inferenceCount: number;           // Incremented for every inference made (whether new or not)
         inferences: Type[][];             // Inferences made for each type parameter
         inferredTypes: Type[];            // Inferred type for each type parameter
+        failureIndex?: number;            // Index of type parameter for which inference failed
+                                          // It is optional because in contextual signature instantiation, nothing fails
     }
 
     export interface DiagnosticMessage {

tests/baselines/reference/contextualTypingWithFixedTypeParameters1.errors.txt

@@ -1,5 +1,6 @@
 tests/cases/compiler/contextualTypingWithFixedTypeParameters1.ts(2,22): error TS2339: Property 'foo' does not exist on type 'string'.
-tests/cases/compiler/contextualTypingWithFixedTypeParameters1.ts(3,10): error TS2346: Supplied parameters do not match any signature of call target.
+tests/cases/compiler/contextualTypingWithFixedTypeParameters1.ts(3,10): error TS2453: The type argument for type parameter 'T' cannot be inferred from the usage. Consider specifying the type arguments explicitly:
+  Type argument candidate 'string' is not a valid type argument because it is not a supertype of candidate 'number'.
 
 
 ==== tests/cases/compiler/contextualTypingWithFixedTypeParameters1.ts (2 errors) ====
@@ -8,5 +9,6 @@ tests/cases/compiler/contextualTypingWithFixedTypeParameters1.ts(3,10): error TS
                          ~~~
 !!! error TS2339: Property 'foo' does not exist on type 'string'.
     var r9 = f10('', () => (a => a.foo), 1); // error
-             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2346: Supplied parameters do not match any signature of call target.
+             ~~~
+!!! error TS2453: The type argument for type parameter 'T' cannot be inferred from the usage. Consider specifying the type arguments explicitly:
+!!! error TS2453:   Type argument candidate 'string' is not a valid type argument because it is not a supertype of candidate 'number'.

tests/baselines/reference/defaultBestCommonTypesHaveDecls.errors.txt

@@ -1,6 +1,7 @@
 tests/cases/compiler/defaultBestCommonTypesHaveDecls.ts(2,6): error TS2339: Property 'length' does not exist on type '{}'.
 tests/cases/compiler/defaultBestCommonTypesHaveDecls.ts(5,6): error TS2339: Property 'length' does not exist on type 'Object'.
-tests/cases/compiler/defaultBestCommonTypesHaveDecls.ts(8,14): error TS2346: Supplied parameters do not match any signature of call target.
+tests/cases/compiler/defaultBestCommonTypesHaveDecls.ts(8,14): error TS2453: The type argument for type parameter 'T' cannot be inferred from the usage. Consider specifying the type arguments explicitly:
+  Type argument candidate 'number' is not a valid type argument because it is not a supertype of candidate 'string'.
 
 
 ==== tests/cases/compiler/defaultBestCommonTypesHaveDecls.ts (3 errors) ====
@@ -16,8 +17,9 @@ tests/cases/compiler/defaultBestCommonTypesHaveDecls.ts(8,14): error TS2346: Sup
 
     function concat<T>(x: T, y: T): T { return null; }
     var result = concat(1, ""); // error
-                 ~~~~~~~~~~~~~
-!!! error TS2346: Supplied parameters do not match any signature of call target.
+                 ~~~~~~
+!!! error TS2453: The type argument for type parameter 'T' cannot be inferred from the usage. Consider specifying the type arguments explicitly:
+!!! error TS2453:   Type argument candidate 'number' is not a valid type argument because it is not a supertype of candidate 'string'.
     var elementCount = result.length; 
 
     function concat2<T, U>(x: T, y: U) { return null; }

tests/baselines/reference/fixTypeParameterInSignatureWithRestParameters.errors.txt

@@ -1,8 +1,10 @@
-tests/cases/compiler/fixTypeParameterInSignatureWithRestParameters.ts(2,1): error TS2346: Supplied parameters do not match any signature of call target.
+tests/cases/compiler/fixTypeParameterInSignatureWithRestParameters.ts(2,1): error TS2453: The type argument for type parameter 'T' cannot be inferred from the usage. Consider specifying the type arguments explicitly:
+  Type argument candidate 'number' is not a valid type argument because it is not a supertype of candidate 'string'.
 
 
 ==== tests/cases/compiler/fixTypeParameterInSignatureWithRestParameters.ts (1 errors) ====
     function bar<T>(item1: T, item2: T) { }
     bar(1, ""); // Should be ok
-    ~~~~~~~~~~
-!!! error TS2346: Supplied parameters do not match any signature of call target.
+    ~~~
+!!! error TS2453: The type argument for type parameter 'T' cannot be inferred from the usage. Consider specifying the type arguments explicitly:
+!!! error TS2453:   Type argument candidate 'number' is not a valid type argument because it is not a supertype of candidate 'string'.

tests/baselines/reference/genericCallWithFunctionTypedArguments.errors.txt

@@ -1,10 +1,13 @@
-tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithFunctionTypedArguments.ts(26,18): error TS2345: Argument of type '(a: number) => string' is not assignable to parameter of type '(a: number) => number'.
-  Type 'string' is not assignable to type 'number'.
-tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithFunctionTypedArguments.ts(30,15): error TS2346: Supplied parameters do not match any signature of call target.
-tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithFunctionTypedArguments.ts(33,15): error TS2346: Supplied parameters do not match any signature of call target.
-tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithFunctionTypedArguments.ts(34,16): error TS2346: Supplied parameters do not match any signature of call target.
-tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithFunctionTypedArguments.ts(35,23): error TS2345: Argument of type '(a: number) => string' is not assignable to parameter of type '(a: number) => number'.
-  Type 'string' is not assignable to type 'number'.
+tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithFunctionTypedArguments.ts(26,10): error TS2453: The type argument for type parameter 'U' cannot be inferred from the usage. Consider specifying the type arguments explicitly:
+  Type argument candidate 'number' is not a valid type argument because it is not a supertype of candidate 'string'.
+tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithFunctionTypedArguments.ts(30,15): error TS2453: The type argument for type parameter 'T' cannot be inferred from the usage. Consider specifying the type arguments explicitly:
+  Type argument candidate 'number' is not a valid type argument because it is not a supertype of candidate 'T'.
+tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithFunctionTypedArguments.ts(33,15): error TS2453: The type argument for type parameter 'T' cannot be inferred from the usage. Consider specifying the type arguments explicitly:
+  Type argument candidate 'number' is not a valid type argument because it is not a supertype of candidate 'T'.
+tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithFunctionTypedArguments.ts(34,16): error TS2453: The type argument for type parameter 'T' cannot be inferred from the usage. Consider specifying the type arguments explicitly:
+  Type argument candidate 'number' is not a valid type argument because it is not a supertype of candidate 'T'.
+tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithFunctionTypedArguments.ts(35,15): error TS2453: The type argument for type parameter 'U' cannot be inferred from the usage. Consider specifying the type arguments explicitly:
+  Type argument candidate 'number' is not a valid type argument because it is not a supertype of candidate 'string'.
 
 
 ==== tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithFunctionTypedArguments.ts (5 errors) ====
@@ -34,25 +37,28 @@ tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithFun
     var r7 = foo3(1, <Z>(a: Z) => '', ''); // string
 
     var r8 = foo3(1, function (a) { return '' }, 1); // error
-                     ~~~~~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2345: Argument of type '(a: number) => string' is not assignable to parameter of type '(a: number) => number'.
-!!! error TS2345:   Type 'string' is not assignable to type 'number'.
+             ~~~~
+!!! error TS2453: The type argument for type parameter 'U' cannot be inferred from the usage. Consider specifying the type arguments explicitly:
+!!! error TS2453:   Type argument candidate 'number' is not a valid type argument because it is not a supertype of candidate 'string'.
     var r9 = foo3<number, string>(1, (a) => '', ''); // string
 
     function other<T, U>(t: T, u: U) {
         var r10 = foo2(1, (x: T) => ''); // error
-                  ~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2346: Supplied parameters do not match any signature of call target.
+                  ~~~~
+!!! error TS2453: The type argument for type parameter 'T' cannot be inferred from the usage. Consider specifying the type arguments explicitly:
+!!! error TS2453:   Type argument candidate 'number' is not a valid type argument because it is not a supertype of candidate 'T'.
         var r10 = foo2(1, (x) => ''); // string
 
         var r11 = foo3(1, (x: T) => '', ''); // error
-                  ~~~~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2346: Supplied parameters do not match any signature of call target.
+                  ~~~~
+!!! error TS2453: The type argument for type parameter 'T' cannot be inferred from the usage. Consider specifying the type arguments explicitly:
+!!! error TS2453:   Type argument candidate 'number' is not a valid type argument because it is not a supertype of candidate 'T'.
         var r11b = foo3(1, (x: T) => '', 1); // error
-                   ~~~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2346: Supplied parameters do not match any signature of call target.
+                   ~~~~
+!!! error TS2453: The type argument for type parameter 'T' cannot be inferred from the usage. Consider specifying the type arguments explicitly:
+!!! error TS2453:   Type argument candidate 'number' is not a valid type argument because it is not a supertype of candidate 'T'.
         var r12 = foo3(1, function (a) { return '' }, 1); // error
-                          ~~~~~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2345: Argument of type '(a: number) => string' is not assignable to parameter of type '(a: number) => number'.
-!!! error TS2345:   Type 'string' is not assignable to type 'number'.
+                  ~~~~
+!!! error TS2453: The type argument for type parameter 'U' cannot be inferred from the usage. Consider specifying the type arguments explicitly:
+!!! error TS2453:   Type argument candidate 'number' is not a valid type argument because it is not a supertype of candidate 'string'.
     }

tests/baselines/reference/genericCallWithFunctionTypedArguments2.errors.txt

@@ -1,5 +1,7 @@
-tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithFunctionTypedArguments2.ts(29,10): error TS2346: Supplied parameters do not match any signature of call target.
-tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithFunctionTypedArguments2.ts(40,10): error TS2346: Supplied parameters do not match any signature of call target.
+tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithFunctionTypedArguments2.ts(29,10): error TS2453: The type argument for type parameter 'T' cannot be inferred from the usage. Consider specifying the type arguments explicitly:
+  Type argument candidate 'number' is not a valid type argument because it is not a supertype of candidate 'string'.
+tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithFunctionTypedArguments2.ts(40,10): error TS2453: The type argument for type parameter 'T' cannot be inferred from the usage. Consider specifying the type arguments explicitly:
+  Type argument candidate 'number' is not a valid type argument because it is not a supertype of candidate 'string'.
 
 
 ==== tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithFunctionTypedArguments2.ts (2 errors) ====
@@ -32,8 +34,9 @@ tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithFun
     }
 
     var r4 = foo2(1, i2); // error
-             ~~~~~~~~~~~
-!!! error TS2346: Supplied parameters do not match any signature of call target.
+             ~~~~
+!!! error TS2453: The type argument for type parameter 'T' cannot be inferred from the usage. Consider specifying the type arguments explicitly:
+!!! error TS2453:   Type argument candidate 'number' is not a valid type argument because it is not a supertype of candidate 'string'.
     var r4b = foo2(1, a); // any
     var r5 = foo2(1, i); // any
     var r6 = foo2<string, string>('', i2); // string
@@ -45,6 +48,7 @@ tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithFun
     var r7 = foo3(null, i, ''); // any
     var r7b = foo3(null, a, ''); // any
     var r8 = foo3(1, i2, 1); // error
-             ~~~~~~~~~~~~~~
-!!! error TS2346: Supplied parameters do not match any signature of call target.
+             ~~~~
+!!! error TS2453: The type argument for type parameter 'T' cannot be inferred from the usage. Consider specifying the type arguments explicitly:
+!!! error TS2453:   Type argument candidate 'number' is not a valid type argument because it is not a supertype of candidate 'string'.
     var r9 = foo3<string, string>('', i2, ''); // string

tests/baselines/reference/genericCallWithGenericSignatureArguments.errors.txt

@@ -1,5 +1,7 @@
-tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithGenericSignatureArguments.ts(18,10): error TS2346: Supplied parameters do not match any signature of call target.
-tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithGenericSignatureArguments.ts(19,10): error TS2346: Supplied parameters do not match any signature of call target.
+tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithGenericSignatureArguments.ts(18,10): error TS2453: The type argument for type parameter 'T' cannot be inferred from the usage. Consider specifying the type arguments explicitly:
+  Type argument candidate '{ x: number; y?: number; }' is not a valid type argument because it is not a supertype of candidate '{ x: number; z?: number; }'.
+tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithGenericSignatureArguments.ts(19,10): error TS2453: The type argument for type parameter 'T' cannot be inferred from the usage. Consider specifying the type arguments explicitly:
+  Type argument candidate '{ x: number; z?: number; }' is not a valid type argument because it is not a supertype of candidate '{ x: number; y?: number; }'.
 
 
 ==== tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithGenericSignatureArguments.ts (2 errors) ====
@@ -21,11 +23,13 @@ tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithGen
     var b: { x: number; z?: number; };
 
     var r4 = foo((x: typeof a) => a, (x: typeof b) => b); // typeof a => typeof a
-             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2346: Supplied parameters do not match any signature of call target.
+             ~~~
+!!! error TS2453: The type argument for type parameter 'T' cannot be inferred from the usage. Consider specifying the type arguments explicitly:
+!!! error TS2453:   Type argument candidate '{ x: number; y?: number; }' is not a valid type argument because it is not a supertype of candidate '{ x: number; z?: number; }'.
     var r5 = foo((x: typeof b) => b, (x: typeof a) => a); // typeof b => typeof b
-             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2346: Supplied parameters do not match any signature of call target.
+             ~~~
+!!! error TS2453: The type argument for type parameter 'T' cannot be inferred from the usage. Consider specifying the type arguments explicitly:
+!!! error TS2453:   Type argument candidate '{ x: number; z?: number; }' is not a valid type argument because it is not a supertype of candidate '{ x: number; y?: number; }'.
 
     function other<T>(x: T) {
         var r6 = foo((a: T) => a, (b: T) => b); // T => T