func-call-spacing.ts

import { TSESTree } from '@typescript-eslint/experimental-utils';
import { isOpeningParenToken } from 'eslint-utils';
import * as util from '../util';

export type Options = [
  'never' | 'always',
  {
    allowNewlines?: boolean;
  }?
];
export type MessageIds = 'unexpected' | 'missing';

export default util.createRule<Options, MessageIds>({
  name: 'func-call-spacing',
  meta: {
    type: 'layout',
    docs: {
      description:
        'require or disallow spacing between function identifiers and their invocations',
      category: 'Stylistic Issues',
      recommended: false,
    },
    fixable: 'whitespace',
    schema: {
      anyOf: [
        {
          type: 'array',
          items: [
            {
              enum: ['never'],
            },
          ],
          minItems: 0,
          maxItems: 1,
        },
        {
          type: 'array',
          items: [
            {
              enum: ['always'],
            },
            {
              type: 'object',
              properties: {
                allowNewlines: {
                  type: 'boolean',
                },
              },
              additionalProperties: false,
            },
          ],
          minItems: 0,
          maxItems: 2,
        },
      ],
    },

    messages: {
      unexpected:
        'Unexpected space or newline between function name and paren.',
      missing: 'Missing space between function name and paren.',
    },
  },
  defaultOptions: ['never', {}],
  create(context, [option, config]) {
    const sourceCode = context.getSourceCode();
    const text = sourceCode.getText();

    /**
     * Check if open space is present in a function name
     * @param {ASTNode} node node to evaluate
     * @returns {void}
     * @private
     */
    function checkSpacing(
      node: TSESTree.CallExpression | TSESTree.NewExpression,
    ): void {
      const closingParenToken = sourceCode.getLastToken(node)!;
      const lastCalleeTokenWithoutPossibleParens = sourceCode.getLastToken(
        node.typeParameters || node.callee,
      )!;
      const openingParenToken = sourceCode.getFirstTokenBetween(
        lastCalleeTokenWithoutPossibleParens,
        closingParenToken,
        isOpeningParenToken,
      );
      if (!openingParenToken || openingParenToken.range[1] >= node.range[1]) {
        // new expression with no parens...
        return;
      }
      const lastCalleeToken = sourceCode.getTokenBefore(openingParenToken)!;

      const textBetweenTokens = text
        .slice(lastCalleeToken.range[1], openingParenToken.range[0])
        .replace(/\/\*.*?\*\//gu, '');
      const hasWhitespace = /\s/u.test(textBetweenTokens);
      const hasNewline =
        hasWhitespace && util.LINEBREAK_MATCHER.test(textBetweenTokens);

      if (option === 'never') {
        if (hasWhitespace) {
          return context.report({
            node,
            loc: lastCalleeToken.loc.start,
            messageId: 'unexpected',
            fix(fixer) {
              /*
               * Only autofix if there is no newline
               * https://github.com/eslint/eslint/issues/7787
               */
              if (!hasNewline) {
                return fixer.removeRange([
                  lastCalleeToken.range[1],
                  openingParenToken.range[0],
                ]);
              }

              return null;
            },
          });
        }
      } else {
        if (!hasWhitespace) {
          context.report({
            node,
            loc: lastCalleeToken.loc.start,
            messageId: 'missing',
            fix(fixer) {
              return fixer.insertTextBefore(openingParenToken, ' ');
            },
          });
        } else if (!config!.allowNewlines && hasNewline) {
          context.report({
            node,
            loc: lastCalleeToken.loc.start,
            messageId: 'unexpected',
            fix(fixer) {
              return fixer.replaceTextRange(
                [lastCalleeToken.range[1], openingParenToken.range[0]],
                ' ',
              );
            },
          });
        }
      }
    }

    return {
      CallExpression: checkSpacing,
      NewExpression: checkSpacing,
    };
  },
});