Function checkGrammarIndexSignatureParameters

test/fixtures/snapshot/typescript.js:88122–88159

(node)

            return startLine !== endLine && grammarErrorOnNode(equalsGreaterThanToken, ts.Diagnostics.Line_terminator_not_permitted_before_arrow);
        }
        function checkGrammarIndexSignatureParameters(node) {
            var parameter = node.parameters[0];
            if (node.parameters.length !== 1) {
                if (parameter) {
                    return grammarErrorOnNode(parameter.name, ts.Diagnostics.An_index_signature_must_have_exactly_one_parameter);
                }
                else {
                    return grammarErrorOnNode(node, ts.Diagnostics.An_index_signature_must_have_exactly_one_parameter);
                }
            }
            checkGrammarForDisallowedTrailingComma(node.parameters, ts.Diagnostics.An_index_signature_cannot_have_a_trailing_comma);
            if (parameter.dotDotDotToken) {
                return grammarErrorOnNode(parameter.dotDotDotToken, ts.Diagnostics.An_index_signature_cannot_have_a_rest_parameter);
            }
            if (ts.hasEffectiveModifiers(parameter)) {
                return grammarErrorOnNode(parameter.name, ts.Diagnostics.An_index_signature_parameter_cannot_have_an_accessibility_modifier);
            }
            if (parameter.questionToken) {
                return grammarErrorOnNode(parameter.questionToken, ts.Diagnostics.An_index_signature_parameter_cannot_have_a_question_mark);
            }
            if (parameter.initializer) {
                return grammarErrorOnNode(parameter.name, ts.Diagnostics.An_index_signature_parameter_cannot_have_an_initializer);
            }
            if (!parameter.type) {
                return grammarErrorOnNode(parameter.name, ts.Diagnostics.An_index_signature_parameter_must_have_a_type_annotation);
            }
            var type = getTypeFromTypeNode(parameter.type);
            if (someType(type, function (t) { return !!(t.flags & 8576 /* TypeFlags.StringOrNumberLiteralOrUnique */); }) || isGenericType(type)) {
                return grammarErrorOnNode(parameter.name, ts.Diagnostics.An_index_signature_parameter_type_cannot_be_a_literal_type_or_generic_type_Consider_using_a_mapped_object_type_instead);
            }
            if (!everyType(type, isValidIndexKeyType)) {
                return grammarErrorOnNode(parameter.name, ts.Diagnostics.An_index_signature_parameter_type_must_be_string_number_symbol_or_a_template_literal_type);
            }
            if (!node.type) {
                return grammarErrorOnNode(node, ts.Diagnostics.An_index_signature_must_have_a_type_annotation);
            }
            return false;
        }
        function checkGrammarIndexSignature(node) {
            // Prevent cascading error by short-circuit
            return checkGrammarDecoratorsAndModifiers(node) || checkGrammarIndexSignatureParameters(node);