Report primitive type in literal-to-primitive relation complaints

src/compiler/checker.ts

@@ -4139,12 +4139,16 @@ namespace ts {
             let leftStr = symbolValueDeclarationIsContextSensitive(left.symbol) ? typeToString(left, left.symbol.valueDeclaration) : typeToString(left);
             let rightStr = symbolValueDeclarationIsContextSensitive(right.symbol) ? typeToString(right, right.symbol.valueDeclaration) : typeToString(right);
             if (leftStr === rightStr) {
-                leftStr = typeToString(left, /*enclosingDeclaration*/ undefined, TypeFormatFlags.UseFullyQualifiedType);
-                rightStr = typeToString(right, /*enclosingDeclaration*/ undefined, TypeFormatFlags.UseFullyQualifiedType);
+                leftStr = getTypeNameForErrorDisplay(left);
+                rightStr = getTypeNameForErrorDisplay(right);
             }
             return [leftStr, rightStr];
         }
 
+        function getTypeNameForErrorDisplay(type: Type) {
+            return typeToString(type, /*enclosingDeclaration*/ undefined, TypeFormatFlags.UseFullyQualifiedType);
+        }
+
         function symbolValueDeclarationIsContextSensitive(symbol: Symbol): boolean {
             return symbol && symbol.valueDeclaration && isExpression(symbol.valueDeclaration) && !isContextSensitive(symbol.valueDeclaration);
         }
@@ -15726,23 +15730,30 @@ namespace ts {
             function reportRelationError(message: DiagnosticMessage | undefined, source: Type, target: Type) {
                 if (incompatibleStack.length) reportIncompatibleStack();
                 const [sourceType, targetType] = getTypeNamesForErrorDisplay(source, target);
+                let generalizedSource = source;
+                let generalizedSourceType = sourceType;
+
+                if (isLiteralType(source) && !typeCouldHaveTopLevelSingletonTypes(target)) {
+                    generalizedSource = getBaseTypeOfLiteralType(source);
+                    generalizedSourceType = getTypeNameForErrorDisplay(generalizedSource);
+                }
 
                 if (target.flags & TypeFlags.TypeParameter) {
                     const constraint = getBaseConstraintOfType(target);
-                    const constraintElab = constraint && isTypeAssignableTo(source, constraint);
-                    if (constraintElab) {
+                    let needsOriginalSource;
+                    if (constraint && (isTypeAssignableTo(generalizedSource, constraint) || (needsOriginalSource = isTypeAssignableTo(source, constraint)))) {
                         reportError(
                             Diagnostics._0_is_assignable_to_the_constraint_of_type_1_but_1_could_be_instantiated_with_a_different_subtype_of_constraint_2,
-                            sourceType,
+                            needsOriginalSource ? sourceType : generalizedSourceType,
                             targetType,
-                            typeToString(constraint!),
+                            typeToString(constraint),
                         );
                     }
                     else {
                         reportError(
                             Diagnostics._0_could_be_instantiated_with_an_arbitrary_type_which_could_be_unrelated_to_1,
                             targetType,
-                            sourceType
+                            generalizedSourceType
                         );
                     }
                 }
@@ -15759,7 +15770,7 @@ namespace ts {
                     }
                 }
 
-                reportError(message, sourceType, targetType);
+                reportError(message, generalizedSourceType, targetType);
             }
 
             function tryElaborateErrorsForPrimitivesAndObjects(source: Type, target: Type) {
@@ -17356,6 +17367,21 @@ namespace ts {
             }
         }
 
+        function typeCouldHaveTopLevelSingletonTypes(type: Type): boolean {
+            if (type.flags & TypeFlags.UnionOrIntersection) {
+                return !!forEach((type as IntersectionType).types, typeCouldHaveTopLevelSingletonTypes);
+            }
+
+            if (type.flags & TypeFlags.Instantiable) {
+                const constraint = getConstraintOfType(type);
+                if (constraint) {
+                    return typeCouldHaveTopLevelSingletonTypes(constraint);
+                }
+            }
+
+            return isUnitType(type);
+        }
+
         function getBestMatchingType(source: Type, target: UnionOrIntersectionType, isRelatedTo = compareTypesAssignable) {
             return findMatchingDiscriminantType(source, target, isRelatedTo, /*skipPartial*/ true) ||
                 findMatchingTypeReferenceOrTypeAliasReference(source, target) ||

src/testRunner/unittests/tscWatch/incremental.ts

@@ -196,7 +196,7 @@ namespace ts.tscWatch {
                         length: 1,
                         code: Diagnostics.Type_0_is_not_assignable_to_type_1.code,
                         category: Diagnostics.Type_0_is_not_assignable_to_type_1.category,
-                        messageText: "Type '20' is not assignable to type 'string'.",
+                        messageText: "Type 'number' is not assignable to type 'string'.",
                         relatedInformation: undefined,
                         reportsUnnecessary: undefined,
                         source: undefined

src/testRunner/unittests/tscWatch/resolutionCache.ts

@@ -37,7 +37,7 @@ namespace ts.tscWatch {
                 // ensure file has correct number of errors after edit
                 checkOutputErrorsIncremental(host, [
                     f1IsNotModule,
-                    getDiagnosticOfFileFromProgram(watch.getCurrentProgram().getProgram(), root.path, newContent.indexOf("var x") + "var ".length, "x".length, Diagnostics.Type_0_is_not_assignable_to_type_1, 1, "string"),
+                    getDiagnosticOfFileFromProgram(watch.getCurrentProgram().getProgram(), root.path, newContent.indexOf("var x") + "var ".length, "x".length, Diagnostics.Type_0_is_not_assignable_to_type_1, "number", "string"),
                     cannotFindFoo
                 ]);
             }

src/testRunner/unittests/tsserver/openFile.ts

@@ -175,7 +175,7 @@ bar();`
                         file,
                         syntax: [],
                         semantic: [
-                            createDiagnostic(locationOfY.start, locationOfY.end, Diagnostics.Type_0_is_not_assignable_to_type_1, ["10", "string"]),
+                            createDiagnostic(locationOfY.start, locationOfY.end, Diagnostics.Type_0_is_not_assignable_to_type_1, ["number", "string"]),
                         ],
                         suggestion: []
                     },

src/testRunner/unittests/tsserver/projectReferenceErrors.ts

@@ -166,7 +166,7 @@ fnErr();
                             { line: 6, offset: 12 },
                             { line: 6, offset: 13 },
                             Diagnostics.Type_0_is_not_assignable_to_type_1,
-                            ["10", "string"],
+                            ["number", "string"],
                             "error",
                         )
                     ],
@@ -235,7 +235,7 @@ fnErr();
                             { line: 6, offset: 5 },
                             { line: 6, offset: 6 },
                             Diagnostics.Type_0_is_not_assignable_to_type_1,
-                            ["10", "string"],
+                            ["number", "string"],
                             "error",
                         )
                     ],

tests/baselines/reference/ES5For-of30.errors.txt

@@ -1,6 +1,6 @@
 tests/cases/conformance/statements/for-ofStatements/ES5For-of30.ts(3,6): error TS2461: Type 'string | number' is not an array type.
-tests/cases/conformance/statements/for-ofStatements/ES5For-of30.ts(3,7): error TS2322: Type '1' is not assignable to type 'string'.
-tests/cases/conformance/statements/for-ofStatements/ES5For-of30.ts(3,14): error TS2322: Type '""' is not assignable to type 'number'.
+tests/cases/conformance/statements/for-ofStatements/ES5For-of30.ts(3,7): error TS2322: Type 'number' is not assignable to type 'string'.
+tests/cases/conformance/statements/for-ofStatements/ES5For-of30.ts(3,14): error TS2322: Type 'string' is not assignable to type 'number'.
 
 
 ==== tests/cases/conformance/statements/for-ofStatements/ES5For-of30.ts (3 errors) ====
@@ -10,9 +10,9 @@ tests/cases/conformance/statements/for-ofStatements/ES5For-of30.ts(3,14): error
          ~~~~~~~~~~~~~~~
 !!! error TS2461: Type 'string | number' is not an array type.
           ~
-!!! error TS2322: Type '1' is not assignable to type 'string'.
+!!! error TS2322: Type 'number' is not assignable to type 'string'.
                  ~
-!!! error TS2322: Type '""' is not assignable to type 'number'.
+!!! error TS2322: Type 'string' is not assignable to type 'number'.
         a;
         b;
     }

tests/baselines/reference/accessors_spec_section-4.5_error-cases.errors.txt

@@ -1,14 +1,14 @@
 tests/cases/compiler/accessors_spec_section-4.5_error-cases.ts(2,16): error TS1056: Accessors are only available when targeting ECMAScript 5 and higher.
 tests/cases/compiler/accessors_spec_section-4.5_error-cases.ts(3,16): error TS1056: Accessors are only available when targeting ECMAScript 5 and higher.
-tests/cases/compiler/accessors_spec_section-4.5_error-cases.ts(3,48): error TS2322: Type '""' is not assignable to type 'number'.
+tests/cases/compiler/accessors_spec_section-4.5_error-cases.ts(3,48): error TS2322: Type 'string' is not assignable to type 'number'.
 tests/cases/compiler/accessors_spec_section-4.5_error-cases.ts(5,16): error TS1056: Accessors are only available when targeting ECMAScript 5 and higher.
-tests/cases/compiler/accessors_spec_section-4.5_error-cases.ts(5,47): error TS2322: Type '""' is not assignable to type 'number'.
+tests/cases/compiler/accessors_spec_section-4.5_error-cases.ts(5,47): error TS2322: Type 'string' is not assignable to type 'number'.
 tests/cases/compiler/accessors_spec_section-4.5_error-cases.ts(6,16): error TS1056: Accessors are only available when targeting ECMAScript 5 and higher.
 tests/cases/compiler/accessors_spec_section-4.5_error-cases.ts(8,16): error TS1056: Accessors are only available when targeting ECMAScript 5 and higher.
 tests/cases/compiler/accessors_spec_section-4.5_error-cases.ts(9,16): error TS1056: Accessors are only available when targeting ECMAScript 5 and higher.
-tests/cases/compiler/accessors_spec_section-4.5_error-cases.ts(9,52): error TS2322: Type '0' is not assignable to type 'string'.
+tests/cases/compiler/accessors_spec_section-4.5_error-cases.ts(9,52): error TS2322: Type 'number' is not assignable to type 'string'.
 tests/cases/compiler/accessors_spec_section-4.5_error-cases.ts(11,16): error TS1056: Accessors are only available when targeting ECMAScript 5 and higher.
-tests/cases/compiler/accessors_spec_section-4.5_error-cases.ts(11,51): error TS2322: Type '0' is not assignable to type 'string'.
+tests/cases/compiler/accessors_spec_section-4.5_error-cases.ts(11,51): error TS2322: Type 'number' is not assignable to type 'string'.
 tests/cases/compiler/accessors_spec_section-4.5_error-cases.ts(12,16): error TS1056: Accessors are only available when targeting ECMAScript 5 and higher.
 
 
@@ -21,13 +21,13 @@ tests/cases/compiler/accessors_spec_section-4.5_error-cases.ts(12,16): error TS1
                    ~~~~~~~~~~~~~~~~~~~~~~~~~~~
 !!! error TS1056: Accessors are only available when targeting ECMAScript 5 and higher.
                                                    ~~~~~~~~~~
-!!! error TS2322: Type '""' is not assignable to type 'number'.
+!!! error TS2322: Type 'string' is not assignable to type 'number'.
 
         public get AnnotatedSetter_SetterLast() { return ""; }
                    ~~~~~~~~~~~~~~~~~~~~~~~~~~
 !!! error TS1056: Accessors are only available when targeting ECMAScript 5 and higher.
                                                   ~~~~~~~~~~
-!!! error TS2322: Type '""' is not assignable to type 'number'.
+!!! error TS2322: Type 'string' is not assignable to type 'number'.
         public set AnnotatedSetter_SetterLast(a: number) { }
                    ~~~~~~~~~~~~~~~~~~~~~~~~~~
 !!! error TS1056: Accessors are only available when targeting ECMAScript 5 and higher.
@@ -39,13 +39,13 @@ tests/cases/compiler/accessors_spec_section-4.5_error-cases.ts(12,16): error TS1
                    ~~~~~~~~~~~~~~~~~~~~~~~~~~~
 !!! error TS1056: Accessors are only available when targeting ECMAScript 5 and higher.
                                                        ~~~~
-!!! error TS2322: Type '0' is not assignable to type 'string'.
+!!! error TS2322: Type 'number' is not assignable to type 'string'.
 
         public set AnnotatedGetter_GetterLast(aStr) { aStr = 0; }
                    ~~~~~~~~~~~~~~~~~~~~~~~~~~
 !!! error TS1056: Accessors are only available when targeting ECMAScript 5 and higher.
                                                       ~~~~
-!!! error TS2322: Type '0' is not assignable to type 'string'.
+!!! error TS2322: Type 'number' is not assignable to type 'string'.
         public get AnnotatedGetter_GetterLast(): string { return ""; }
                    ~~~~~~~~~~~~~~~~~~~~~~~~~~
 !!! error TS1056: Accessors are only available when targeting ECMAScript 5 and higher.

tests/baselines/reference/aliasAssignments.errors.txt

@@ -1,4 +1,4 @@
-tests/cases/compiler/aliasAssignments_1.ts(3,1): error TS2322: Type '1' is not assignable to type 'typeof import("tests/cases/compiler/aliasAssignments_moduleA")'.
+tests/cases/compiler/aliasAssignments_1.ts(3,1): error TS2322: Type 'number' is not assignable to type 'typeof import("tests/cases/compiler/aliasAssignments_moduleA")'.
 tests/cases/compiler/aliasAssignments_1.ts(5,1): error TS2322: Type 'typeof import("tests/cases/compiler/aliasAssignments_moduleA")' is not assignable to type 'number'.
 
 
@@ -7,7 +7,7 @@ tests/cases/compiler/aliasAssignments_1.ts(5,1): error TS2322: Type 'typeof impo
     var x = moduleA;
     x = 1; // Should be error
     ~
-!!! error TS2322: Type '1' is not assignable to type 'typeof import("tests/cases/compiler/aliasAssignments_moduleA")'.
+!!! error TS2322: Type 'number' is not assignable to type 'typeof import("tests/cases/compiler/aliasAssignments_moduleA")'.
     var y = 1;
     y = moduleA; // should be error
     ~

tests/baselines/reference/allowJscheckJsTypeParameterNoCrash.errors.txt

@@ -1,4 +1,4 @@
-tests/cases/compiler/app.js(6,7): error TS2322: Type '1' is not assignable to type 'WatchHandler<any>'.
+tests/cases/compiler/app.js(6,7): error TS2322: Type 'number' is not assignable to type 'WatchHandler<any>'.
 
 
 ==== tests/cases/compiler/func.ts (0 errors) ====
@@ -16,7 +16,7 @@ tests/cases/compiler/app.js(6,7): error TS2322: Type '1' is not assignable to ty
         data1(val) {
           this.data2 = 1;
           ~~~~~~~~~~
-!!! error TS2322: Type '1' is not assignable to type 'WatchHandler<any>'.
+!!! error TS2322: Type 'number' is not assignable to type 'WatchHandler<any>'.
         },
         data2(val) { },
       }

tests/baselines/reference/argumentsBindsToFunctionScopeArgumentList.errors.txt

@@ -1,10 +1,10 @@
-tests/cases/compiler/argumentsBindsToFunctionScopeArgumentList.ts(3,5): error TS2322: Type '10' is not assignable to type 'IArguments'.
+tests/cases/compiler/argumentsBindsToFunctionScopeArgumentList.ts(3,5): error TS2322: Type 'number' is not assignable to type 'IArguments'.
 
 
 ==== tests/cases/compiler/argumentsBindsToFunctionScopeArgumentList.ts (1 errors) ====
     var arguments = 10;
     function foo(a) {
         arguments = 10;  /// This shouldnt be of type number and result in error.
         ~~~~~~~~~
-!!! error TS2322: Type '10' is not assignable to type 'IArguments'.
+!!! error TS2322: Type 'number' is not assignable to type 'IArguments'.
     }

tests/baselines/reference/arrayLiterals3.errors.txt

@@ -1,7 +1,7 @@
 tests/cases/conformance/expressions/arrayLiterals/arrayLiterals3.ts(10,5): error TS2739: Type '[]' is missing the following properties from type '[any, any, any]': 0, 1, 2
 tests/cases/conformance/expressions/arrayLiterals/arrayLiterals3.ts(11,38): error TS2322: Type 'string' is not assignable to type 'boolean'.
 tests/cases/conformance/expressions/arrayLiterals/arrayLiterals3.ts(11,48): error TS2322: Type 'number' is not assignable to type 'string'.
-tests/cases/conformance/expressions/arrayLiterals/arrayLiterals3.ts(11,51): error TS2322: Type 'true' is not assignable to type 'number'.
+tests/cases/conformance/expressions/arrayLiterals/arrayLiterals3.ts(11,51): error TS2322: Type 'boolean' is not assignable to type 'number'.
 tests/cases/conformance/expressions/arrayLiterals/arrayLiterals3.ts(17,5): error TS2322: Type '[number, number, string, boolean]' is not assignable to type '[number, number]'.
   Types of property 'length' are incompatible.
     Type '4' is not assignable to type '2'.
@@ -31,7 +31,7 @@ tests/cases/conformance/expressions/arrayLiterals/arrayLiterals3.ts(34,5): error
                                                    ~
 !!! error TS2322: Type 'number' is not assignable to type 'string'.
                                                       ~~~~
-!!! error TS2322: Type 'true' is not assignable to type 'number'.
+!!! error TS2322: Type 'boolean' is not assignable to type 'number'.
 
     // The resulting type an array literal expression is determined as follows:
     //     - If the array literal contains no spread elements and is an array assignment pattern in a destructuring assignment (section 4.17.1),

tests/baselines/reference/assignToFn.errors.txt

@@ -1,4 +1,4 @@
-tests/cases/compiler/assignToFn.ts(8,5): error TS2322: Type '"hello"' is not assignable to type '(n: number) => boolean'.
+tests/cases/compiler/assignToFn.ts(8,5): error TS2322: Type 'string' is not assignable to type '(n: number) => boolean'.
 
 
 ==== tests/cases/compiler/assignToFn.ts (1 errors) ====
@@ -11,6 +11,6 @@ tests/cases/compiler/assignToFn.ts(8,5): error TS2322: Type '"hello"' is not ass
 
         x.f="hello";
         ~~~
-!!! error TS2322: Type '"hello"' is not assignable to type '(n: number) => boolean'.
+!!! error TS2322: Type 'string' is not assignable to type '(n: number) => boolean'.
     }
 

tests/baselines/reference/assignmentCompat1.errors.txt

@@ -1,7 +1,7 @@
 tests/cases/compiler/assignmentCompat1.ts(4,1): error TS2741: Property 'one' is missing in type '{ [index: string]: any; }' but required in type '{ one: number; }'.
 tests/cases/compiler/assignmentCompat1.ts(6,1): error TS2741: Property 'one' is missing in type '{ [index: number]: any; }' but required in type '{ one: number; }'.
-tests/cases/compiler/assignmentCompat1.ts(8,1): error TS2322: Type '"foo"' is not assignable to type '{ [index: string]: any; }'.
-tests/cases/compiler/assignmentCompat1.ts(10,1): error TS2322: Type 'false' is not assignable to type '{ [index: number]: any; }'.
+tests/cases/compiler/assignmentCompat1.ts(8,1): error TS2322: Type 'string' is not assignable to type '{ [index: string]: any; }'.
+tests/cases/compiler/assignmentCompat1.ts(10,1): error TS2322: Type 'boolean' is not assignable to type '{ [index: number]: any; }'.
 
 
 ==== tests/cases/compiler/assignmentCompat1.ts (4 errors) ====
@@ -20,10 +20,10 @@ tests/cases/compiler/assignmentCompat1.ts(10,1): error TS2322: Type 'false' is n
     z = x;  // Ok because index signature type is any
     y = "foo"; // Error
     ~
-!!! error TS2322: Type '"foo"' is not assignable to type '{ [index: string]: any; }'.
+!!! error TS2322: Type 'string' is not assignable to type '{ [index: string]: any; }'.
     z = "foo"; // OK, string has numeric indexer
     z = false; // Error
     ~
-!!! error TS2322: Type 'false' is not assignable to type '{ [index: number]: any; }'.
+!!! error TS2322: Type 'boolean' is not assignable to type '{ [index: number]: any; }'.