fixAddMissingMember.ts

/* @internal */
namespace ts.codefix {
    registerCodeFix({
        errorCodes: [Diagnostics.Property_0_does_not_exist_on_type_1.code],
        getCodeActions: getActionsForAddMissingMember
    });

    function getActionsForAddMissingMember(context: CodeFixContext): CodeAction[] | undefined {

        const sourceFile = context.sourceFile;
        const start = context.span.start;
        // This is the identifier of the missing property. eg:
        // this.missing = 1;
        //      ^^^^^^^
        const token = getTokenAtPosition(sourceFile, start);

        if (token.kind != SyntaxKind.Identifier) {
            return undefined;
        }

        const classDeclaration = getContainingClass(token);
        if (!classDeclaration) {
            return undefined;
        }

        if (!(token.parent && token.parent.kind === SyntaxKind.PropertyAccessExpression)) {
            return undefined;
        }

        if ((token.parent as PropertyAccessExpression).expression.kind !== SyntaxKind.ThisKeyword) {
            return undefined;
        }

        let typeString = "any";

        if (token.parent.parent.kind === SyntaxKind.BinaryExpression) {
            const binaryExpression = token.parent.parent as BinaryExpression;

            const checker = context.program.getTypeChecker();
            const widenedType = checker.getBaseTypeOfLiteralType(checker.getTypeAtLocation(binaryExpression.right));
            typeString = checker.typeToString(widenedType);
        }

        const startPos = classDeclaration.members.pos;

        return [{
            description: formatStringFromArgs(getLocaleSpecificMessage(Diagnostics.Add_declaration_for_missing_property_0), [token.getText()]),
            changes: [{
                fileName: sourceFile.fileName,
                textChanges: [{
                    span: { start: startPos, length: 0 },
                    newText: `${token.getFullText(sourceFile)}: ${typeString};`
                }]
            }]
        },
        {
            description: formatStringFromArgs(getLocaleSpecificMessage(Diagnostics.Add_index_accessor_for_missing_property_0), [token.getText()]),
            changes: [{
                fileName: sourceFile.fileName,
                textChanges: [{
                    span: { start: startPos, length: 0 },
                    newText: `[name: string]: ${typeString};`
                }]
            }]
        }];
    }
}