From 9255d551540e2ec216da68224a6ac6ce04408c26 Mon Sep 17 00:00:00 2001 From: Vladimir Matveev Date: Tue, 21 Jul 2015 16:51:08 -0700 Subject: [PATCH] better error message when using forward references in initializers of const enums --- src/compiler/checker.ts | 61 +++++++++++-------- .../diagnosticInformationMap.generated.ts | 1 + src/compiler/diagnosticMessages.json | 4 ++ .../reference/constEnumErrors.errors.txt | 4 +- 4 files changed, 42 insertions(+), 28 deletions(-) diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts index c09b069bee6..9478fed1f6c 100644 --- a/src/compiler/checker.ts +++ b/src/compiler/checker.ts @@ -4363,11 +4363,11 @@ namespace ts { return getInferredType(context, i); } } - return t; + return t; }; mapper.context = context; - return mapper; + return mapper; } function identityMapper(type: Type): Type { @@ -12736,28 +12736,7 @@ namespace ts { } let initializer = member.initializer; if (initializer) { - autoValue = getConstantValueForEnumMemberInitializer(initializer); - if (autoValue === undefined) { - if (enumIsConst) { - error(initializer, Diagnostics.In_const_enum_declarations_member_initializer_must_be_constant_expression); - } - else if (!ambient) { - // Only here do we need to check that the initializer is assignable to the enum type. - // If it is a constant value (not undefined), it is syntactically constrained to be a number. - // Also, we do not need to check this for ambients because there is already - // a syntax error if it is not a constant. - checkTypeAssignableTo(checkExpression(initializer), enumType, initializer, /*headMessage*/ undefined); - } - } - else if (enumIsConst) { - if (isNaN(autoValue)) { - error(initializer, Diagnostics.const_enum_member_initializer_was_evaluated_to_disallowed_value_NaN); - } - else if (!isFinite(autoValue)) { - error(initializer, Diagnostics.const_enum_member_initializer_was_evaluated_to_a_non_finite_value); - } - } - + autoValue = computeConstantValueForEnumMemberInitializer(initializer, enumType, enumIsConst, ambient); } else if (ambient && !enumIsConst) { autoValue = undefined; @@ -12771,8 +12750,36 @@ namespace ts { nodeLinks.flags |= NodeCheckFlags.EnumValuesComputed; } - function getConstantValueForEnumMemberInitializer(initializer: Expression): number { - return evalConstant(initializer); + function computeConstantValueForEnumMemberInitializer(initializer: Expression, enumType: Type, enumIsConst: boolean, ambient: boolean): number { + // Controls if error should be reported after evaluation of constant value is completed + // Can be false if another more precise error was already reported during evaluation. + let reportError = true; + let value = evalConstant(initializer); + + if (reportError) { + if (value === undefined) { + if (enumIsConst) { + error(initializer, Diagnostics.In_const_enum_declarations_member_initializer_must_be_constant_expression); + } + else if (!ambient) { + // Only here do we need to check that the initializer is assignable to the enum type. + // If it is a constant value (not undefined), it is syntactically constrained to be a number. + // Also, we do not need to check this for ambients because there is already + // a syntax error if it is not a constant. + checkTypeAssignableTo(checkExpression(initializer), enumType, initializer, /*headMessage*/ undefined); + } + } + else if (enumIsConst) { + if (isNaN(value)) { + error(initializer, Diagnostics.const_enum_member_initializer_was_evaluated_to_disallowed_value_NaN); + } + else if (!isFinite(value)) { + error(initializer, Diagnostics.const_enum_member_initializer_was_evaluated_to_a_non_finite_value); + } + } + } + + return value; function evalConstant(e: Node): number { switch (e.kind) { @@ -12881,6 +12888,8 @@ namespace ts { // illegal case: forward reference if (!isDefinedBefore(propertyDecl, member)) { + reportError = false; + error(e, Diagnostics.A_member_initializer_in_a_const_enum_declaration_cannot_reference_members_declared_after_it_including_members_defined_in_other_const_enums); return undefined; } diff --git a/src/compiler/diagnosticInformationMap.generated.ts b/src/compiler/diagnosticInformationMap.generated.ts index b91399e8ee1..9007ee44db6 100644 --- a/src/compiler/diagnosticInformationMap.generated.ts +++ b/src/compiler/diagnosticInformationMap.generated.ts @@ -425,6 +425,7 @@ namespace ts { JSX_element_class_does_not_support_attributes_because_it_does_not_have_a_0_property: { code: 2607, category: DiagnosticCategory.Error, key: "JSX element class does not support attributes because it does not have a '{0}' property" }, The_global_type_JSX_0_may_not_have_more_than_one_property: { code: 2608, category: DiagnosticCategory.Error, key: "The global type 'JSX.{0}' may not have more than one property" }, Cannot_emit_namespaced_JSX_elements_in_React: { code: 2650, category: DiagnosticCategory.Error, key: "Cannot emit namespaced JSX elements in React" }, + A_member_initializer_in_a_const_enum_declaration_cannot_reference_members_declared_after_it_including_members_defined_in_other_const_enums: { code: 2474, category: DiagnosticCategory.Error, key: "A member initializer in a 'const' enum declaration cannot reference members declared after it, including members defined in other 'const' enums." }, 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_private_name_1: { code: 4002, category: DiagnosticCategory.Error, key: "Type parameter '{0}' of exported class has or is using private name '{1}'." }, Type_parameter_0_of_exported_interface_has_or_is_using_private_name_1: { code: 4004, category: DiagnosticCategory.Error, key: "Type parameter '{0}' of exported interface has or is using private name '{1}'." }, diff --git a/src/compiler/diagnosticMessages.json b/src/compiler/diagnosticMessages.json index 9fda73740ba..fa4f30a3557 100644 --- a/src/compiler/diagnosticMessages.json +++ b/src/compiler/diagnosticMessages.json @@ -1689,6 +1689,10 @@ "category": "Error", "code": 2650 }, + "A member initializer in a 'const' enum declaration cannot reference members declared after it, including members defined in other 'const' enums.": { + "category": "Error", + "code": 2474 + }, "Import declaration '{0}' is using private name '{1}'.": { "category": "Error", "code": 4000 diff --git a/tests/baselines/reference/constEnumErrors.errors.txt b/tests/baselines/reference/constEnumErrors.errors.txt index be7dad54eeb..e7d5f347be2 100644 --- a/tests/baselines/reference/constEnumErrors.errors.txt +++ b/tests/baselines/reference/constEnumErrors.errors.txt @@ -1,6 +1,6 @@ tests/cases/compiler/constEnumErrors.ts(1,12): error TS2300: Duplicate identifier 'E'. tests/cases/compiler/constEnumErrors.ts(5,8): error TS2300: Duplicate identifier 'E'. -tests/cases/compiler/constEnumErrors.ts(12,9): error TS2474: In 'const' enum declarations member initializer must be constant expression. +tests/cases/compiler/constEnumErrors.ts(12,9): error TS2474: A member initializer in a 'const' enum declaration cannot reference members declared after it, including members defined in other 'const' enums. tests/cases/compiler/constEnumErrors.ts(14,9): error TS2474: In 'const' enum declarations member initializer must be constant expression. tests/cases/compiler/constEnumErrors.ts(15,10): error TS2474: In 'const' enum declarations member initializer must be constant expression. tests/cases/compiler/constEnumErrors.ts(22,13): error TS2476: A const enum member can only be accessed using a string literal. @@ -31,7 +31,7 @@ tests/cases/compiler/constEnumErrors.ts(42,9): error TS2478: 'const' enum member // forward reference to the element of the same enum X = Y, ~ -!!! error TS2474: In 'const' enum declarations member initializer must be constant expression. +!!! error TS2474: A member initializer in a 'const' enum declaration cannot reference members declared after it, including members defined in other 'const' enums. // forward reference to the element of the same enum Y = E1.Z, ~~~~