Merge branch 'master' into ignoreStringIndexSignaturesOnly

# Conflicts:
#	tests/baselines/reference/keyofAndIndexedAccess2.errors.txt
#	tests/baselines/reference/keyofAndIndexedAccess2.js
#	tests/baselines/reference/keyofAndIndexedAccess2.symbols
#	tests/baselines/reference/keyofAndIndexedAccess2.types
#	tests/cases/conformance/types/keyof/keyofAndIndexedAccess2.ts

src/compiler/builder.ts

@@ -236,10 +236,7 @@ namespace ts {
             }
         });
 
-        if (oldCompilerOptions &&
-            (oldCompilerOptions.outDir !== compilerOptions.outDir ||
-                oldCompilerOptions.declarationDir !== compilerOptions.declarationDir ||
-                (oldCompilerOptions.outFile || oldCompilerOptions.out) !== (compilerOptions.outFile || compilerOptions.out))) {
+        if (oldCompilerOptions && compilerOptionsAffectEmit(compilerOptions, oldCompilerOptions)) {
             // Add all files to affectedFilesPendingEmit since emit changed
             state.affectedFilesPendingEmit = concatenate(state.affectedFilesPendingEmit, newProgram.getSourceFiles().map(f => f.path));
             if (state.affectedFilesPendingEmitIndex === undefined) {

src/compiler/checker.ts

@@ -114,6 +114,11 @@ namespace ts {
             getIdentifierCount: () => sum(host.getSourceFiles(), "identifierCount"),
             getSymbolCount: () => sum(host.getSourceFiles(), "symbolCount") + symbolCount,
             getTypeCount: () => typeCount,
+            getRelationCacheSizes: () => ({
+                assignable: assignableRelation.size,
+                identity: identityRelation.size,
+                subtype: subtypeRelation.size,
+            }),
             isUndefinedSymbol: symbol => symbol === undefinedSymbol,
             isArgumentsSymbol: symbol => symbol === argumentsSymbol,
             isUnknownSymbol: symbol => symbol === unknownSymbol,
@@ -6709,11 +6714,12 @@ namespace ts {
                 const links = getSymbolLinks(symbol);
                 if (!links.lateSymbol && some(symbol.declarations, hasLateBindableName)) {
                     // force late binding of members/exports. This will set the late-bound symbol
+                    const parent = getMergedSymbol(symbol.parent)!;
                     if (some(symbol.declarations, hasStaticModifier)) {
-                        getExportsOfSymbol(symbol.parent!);
+                        getExportsOfSymbol(parent);
                     }
                     else {
-                        getMembersOfSymbol(symbol.parent!);
+                        getMembersOfSymbol(parent);
                     }
                 }
                 return links.lateSymbol || (links.lateSymbol = symbol);
@@ -12043,7 +12049,7 @@ namespace ts {
         }
 
         function isStringIndexSignatureOnlyType(type: Type): boolean {
-            return type.flags & TypeFlags.Object && getPropertiesOfType(type).length === 0 && getIndexInfoOfType(type, IndexKind.String) && !getIndexInfoOfType(type, IndexKind.Number) ||
+            return type.flags & TypeFlags.Object && !isGenericMappedType(type) && getPropertiesOfType(type).length === 0 && getIndexInfoOfType(type, IndexKind.String) && !getIndexInfoOfType(type, IndexKind.Number) ||
                 type.flags & TypeFlags.UnionOrIntersection && every((<UnionOrIntersectionType>type).types, isStringIndexSignatureOnlyType) ||
                 false;
         }
@@ -15016,12 +15022,11 @@ namespace ts {
                     }
                     // If no inferences can be made to K's constraint, infer from a union of the property types
                     // in the source to the template type X.
-                    const valueTypes = compact([
-                        getIndexTypeOfType(source, IndexKind.String),
-                        getIndexTypeOfType(source, IndexKind.Number),
-                        ...map(getPropertiesOfType(source), getTypeOfSymbol)
-                    ]);
-                    inferFromTypes(getUnionType(valueTypes), getTemplateTypeFromMappedType(target));
+                    const propTypes = map(getPropertiesOfType(source), getTypeOfSymbol);
+                    const stringIndexType = getIndexTypeOfType(source, IndexKind.String);
+                    const numberIndexInfo = getNonEnumNumberIndexInfo(source);
+                    const numberIndexType = numberIndexInfo && numberIndexInfo.type;
+                    inferFromTypes(getUnionType(append(append(propTypes, stringIndexType), numberIndexType)), getTemplateTypeFromMappedType(target));
                     return true;
                 }
                 return false;

src/compiler/commandLineParser.ts

@@ -281,6 +281,7 @@ namespace ts {
             name: "declaration",
             shortName: "d",
             type: "boolean",
+            affectsEmit: true,
             showInSimplifiedHelpView: true,
             category: Diagnostics.Basic_Options,
             description: Diagnostics.Generates_corresponding_d_ts_file,
@@ -288,6 +289,7 @@ namespace ts {
         {
             name: "declarationMap",
             type: "boolean",
+            affectsEmit: true,
             showInSimplifiedHelpView: true,
             category: Diagnostics.Basic_Options,
             description: Diagnostics.Generates_a_sourcemap_for_each_corresponding_d_ts_file,
@@ -295,12 +297,14 @@ namespace ts {
         {
             name: "emitDeclarationOnly",
             type: "boolean",
+            affectsEmit: true,
             category: Diagnostics.Advanced_Options,
             description: Diagnostics.Only_emit_d_ts_declaration_files,
         },
         {
             name: "sourceMap",
             type: "boolean",
+            affectsEmit: true,
             showInSimplifiedHelpView: true,
             category: Diagnostics.Basic_Options,
             description: Diagnostics.Generates_corresponding_map_file,
@@ -308,6 +312,7 @@ namespace ts {
         {
             name: "outFile",
             type: "string",
+            affectsEmit: true,
             isFilePath: true,
             paramType: Diagnostics.FILE,
             showInSimplifiedHelpView: true,
@@ -317,6 +322,7 @@ namespace ts {
         {
             name: "outDir",
             type: "string",
+            affectsEmit: true,
             isFilePath: true,
             paramType: Diagnostics.DIRECTORY,
             showInSimplifiedHelpView: true,
@@ -326,6 +332,7 @@ namespace ts {
         {
             name: "rootDir",
             type: "string",
+            affectsEmit: true,
             isFilePath: true,
             paramType: Diagnostics.LOCATION,
             category: Diagnostics.Basic_Options,
@@ -334,6 +341,7 @@ namespace ts {
         {
             name: "composite",
             type: "boolean",
+            affectsEmit: true,
             isTSConfigOnly: true,
             category: Diagnostics.Basic_Options,
             description: Diagnostics.Enable_project_compilation,
@@ -341,6 +349,7 @@ namespace ts {
         {
             name: "tsBuildInfoFile",
             type: "string",
+            affectsEmit: true,
             isFilePath: true,
             paramType: Diagnostics.FILE,
             category: Diagnostics.Basic_Options,
@@ -349,6 +358,7 @@ namespace ts {
         {
             name: "removeComments",
             type: "boolean",
+            affectsEmit: true,
             showInSimplifiedHelpView: true,
             category: Diagnostics.Basic_Options,
             description: Diagnostics.Do_not_emit_comments_to_output,
@@ -356,6 +366,7 @@ namespace ts {
         {
             name: "noEmit",
             type: "boolean",
+            affectsEmit: true,
             showInSimplifiedHelpView: true,
             category: Diagnostics.Basic_Options,
             description: Diagnostics.Do_not_emit_outputs,
@@ -363,12 +374,14 @@ namespace ts {
         {
             name: "importHelpers",
             type: "boolean",
+            affectsEmit: true,
             category: Diagnostics.Basic_Options,
             description: Diagnostics.Import_emit_helpers_from_tslib
         },
         {
             name: "downlevelIteration",
             type: "boolean",
+            affectsEmit: true,
             category: Diagnostics.Basic_Options,
             description: Diagnostics.Provide_full_support_for_iterables_in_for_of_spread_and_destructuring_when_targeting_ES5_or_ES3
         },
@@ -580,6 +593,7 @@ namespace ts {
         {
             name: "sourceRoot",
             type: "string",
+            affectsEmit: true,
             paramType: Diagnostics.LOCATION,
             category: Diagnostics.Source_Map_Options,
             description: Diagnostics.Specify_the_location_where_debugger_should_locate_TypeScript_files_instead_of_source_locations,
@@ -587,6 +601,7 @@ namespace ts {
         {
             name: "mapRoot",
             type: "string",
+            affectsEmit: true,
             paramType: Diagnostics.LOCATION,
             category: Diagnostics.Source_Map_Options,
             description: Diagnostics.Specify_the_location_where_debugger_should_locate_map_files_instead_of_generated_locations,
@@ -594,12 +609,14 @@ namespace ts {
         {
             name: "inlineSourceMap",
             type: "boolean",
+            affectsEmit: true,
             category: Diagnostics.Source_Map_Options,
             description: Diagnostics.Emit_a_single_file_with_source_maps_instead_of_having_a_separate_file
         },
         {
             name: "inlineSources",
             type: "boolean",
+            affectsEmit: true,
             category: Diagnostics.Source_Map_Options,
             description: Diagnostics.Emit_the_source_alongside_the_sourcemaps_within_a_single_file_requires_inlineSourceMap_or_sourceMap_to_be_set
         },
@@ -635,6 +652,7 @@ namespace ts {
         {
             name: "out",
             type: "string",
+            affectsEmit: true,
             isFilePath: false, // This is intentionally broken to support compatability with existing tsconfig files
             // for correct behaviour, please use outFile
             category: Diagnostics.Advanced_Options,
@@ -644,6 +662,7 @@ namespace ts {
         {
             name: "reactNamespace",
             type: "string",
+            affectsEmit: true,
             category: Diagnostics.Advanced_Options,
             description: Diagnostics.Deprecated_Use_jsxFactory_instead_Specify_the_object_invoked_for_createElement_when_targeting_react_JSX_emit
         },
@@ -662,6 +681,7 @@ namespace ts {
         {
             name: "emitBOM",
             type: "boolean",
+            affectsEmit: true,
             category: Diagnostics.Advanced_Options,
             description: Diagnostics.Emit_a_UTF_8_Byte_Order_Mark_BOM_in_the_beginning_of_output_files
         },
@@ -677,6 +697,7 @@ namespace ts {
                 crlf: NewLineKind.CarriageReturnLineFeed,
                 lf: NewLineKind.LineFeed
             }),
+            affectsEmit: true,
             paramType: Diagnostics.NEWLINE,
             category: Diagnostics.Advanced_Options,
             description: Diagnostics.Specify_the_end_of_line_sequence_to_be_used_when_emitting_files_Colon_CRLF_dos_or_LF_unix,
@@ -704,6 +725,7 @@ namespace ts {
         {
             name: "stripInternal",
             type: "boolean",
+            affectsEmit: true,
             category: Diagnostics.Advanced_Options,
             description: Diagnostics.Do_not_emit_declarations_for_code_that_has_an_internal_annotation,
         },
@@ -724,24 +746,28 @@ namespace ts {
         {
             name: "noEmitHelpers",
             type: "boolean",
+            affectsEmit: true,
             category: Diagnostics.Advanced_Options,
             description: Diagnostics.Do_not_generate_custom_helper_functions_like_extends_in_compiled_output
         },
         {
             name: "noEmitOnError",
             type: "boolean",
+            affectsEmit: true,
             category: Diagnostics.Advanced_Options,
             description: Diagnostics.Do_not_emit_outputs_if_any_errors_were_reported,
         },
         {
             name: "preserveConstEnums",
             type: "boolean",
+            affectsEmit: true,
             category: Diagnostics.Advanced_Options,
             description: Diagnostics.Do_not_erase_const_enum_declarations_in_generated_code
         },
         {
             name: "declarationDir",
             type: "string",
+            affectsEmit: true,
             isFilePath: true,
             paramType: Diagnostics.DIRECTORY,
             category: Diagnostics.Advanced_Options,
@@ -826,6 +852,10 @@ namespace ts {
     export const semanticDiagnosticsOptionDeclarations: ReadonlyArray<CommandLineOption> =
         optionDeclarations.filter(option => !!option.affectsSemanticDiagnostics);
 
+    /* @internal */
+    export const affectsEmitOptionDeclarations: ReadonlyArray<CommandLineOption> =
+        optionDeclarations.filter(option => !!option.affectsEmit);
+
     /* @internal */
     export const moduleResolutionOptionDeclarations: ReadonlyArray<CommandLineOption> =
         optionDeclarations.filter(option => !!option.affectsModuleResolution);

src/compiler/program.ts

@@ -927,6 +927,7 @@ namespace ts {
             getIdentifierCount: () => getDiagnosticsProducingTypeChecker().getIdentifierCount(),
             getSymbolCount: () => getDiagnosticsProducingTypeChecker().getSymbolCount(),
             getTypeCount: () => getDiagnosticsProducingTypeChecker().getTypeCount(),
+            getRelationCacheSizes: () => getDiagnosticsProducingTypeChecker().getRelationCacheSizes(),
             getFileProcessingDiagnostics: () => fileProcessingDiagnostics,
             getResolvedTypeReferenceDirectives: () => resolvedTypeReferenceDirectives,
             isSourceFileFromExternalLibrary,

src/compiler/types.ts

@@ -2961,6 +2961,7 @@ namespace ts {
         /* @internal */ getIdentifierCount(): number;
         /* @internal */ getSymbolCount(): number;
         /* @internal */ getTypeCount(): number;
+        /* @internal */ getRelationCacheSizes(): { assignable: number, identity: number, subtype: number };
 
         /* @internal */ getFileProcessingDiagnostics(): DiagnosticCollection;
         /* @internal */ getResolvedTypeReferenceDirectives(): Map<ResolvedTypeReferenceDirective | undefined>;
@@ -3246,6 +3247,7 @@ namespace ts {
         /* @internal */ getIdentifierCount(): number;
         /* @internal */ getSymbolCount(): number;
         /* @internal */ getTypeCount(): number;
+        /* @internal */ getRelationCacheSizes(): { assignable: number, identity: number, subtype: number };
 
         /* @internal */ isArrayType(type: Type): boolean;
         /* @internal */ isTupleType(type: Type): boolean;
@@ -4827,6 +4829,7 @@ namespace ts {
         affectsModuleResolution?: true;                         // currently same effect as `affectsSourceFile`
         affectsBindDiagnostics?: true;                          // true if this affects binding (currently same effect as `affectsSourceFile`)
         affectsSemanticDiagnostics?: true;                      // true if option affects semantic diagnostics
+        affectsEmit?: true;                                     // true if the options affects emit
     }
 
     /* @internal */

src/compiler/utilities.ts

@@ -7320,6 +7320,11 @@ namespace ts {
             semanticDiagnosticsOptionDeclarations.some(option => !isJsonEqual(getCompilerOptionValue(oldOptions, option), getCompilerOptionValue(newOptions, option)));
     }
 
+    export function compilerOptionsAffectEmit(newOptions: CompilerOptions, oldOptions: CompilerOptions): boolean {
+        return oldOptions !== newOptions &&
+            affectsEmitOptionDeclarations.some(option => !isJsonEqual(getCompilerOptionValue(oldOptions, option), getCompilerOptionValue(newOptions, option)));
+    }
+
     export function getCompilerOptionValue(options: CompilerOptions, option: CommandLineOption): unknown {
         return option.strictFlag ? getStrictOptionValue(options, option.name as StrictOptionName) : options[option.name];
     }