feat(eslint-plugin): Add func-call-spacing (#448)

Author: bradzacher

packages/eslint-plugin/README.md

@@ -120,9 +120,10 @@ Then you should add `airbnb` (or `airbnb-base`) to your `extends` section of `.e
 | [`@typescript-eslint/explicit-function-return-type`](./docs/rules/explicit-function-return-type.md)       | Require explicit return types on functions and class methods                                                                                        | :heavy_check_mark: |          |                   |
 | [`@typescript-eslint/explicit-member-accessibility`](./docs/rules/explicit-member-accessibility.md)       | Require explicit accessibility modifiers on class properties and methods (`member-access` from TSLint)                                              | :heavy_check_mark: |          |                   |
 | [`@typescript-eslint/generic-type-naming`](./docs/rules/generic-type-naming.md)                           | Enforces naming of generic type variables                                                                                                           |                    |          |                   |
+| [`@typescript-eslint/func-call-spacing`](./docs/rules/func-call-spacing.md)                               | Spacing between function identifiers and their invocations                                                                                          |                    | :wrench: |                   |
 | [`@typescript-eslint/indent`](./docs/rules/indent.md)                                                     | Enforce consistent indentation (`indent` from TSLint)                                                                                               | :heavy_check_mark: | :wrench: |                   |
 | [`@typescript-eslint/interface-name-prefix`](./docs/rules/interface-name-prefix.md)                       | Require that interface names be prefixed with `I` (`interface-name` from TSLint)                                                                    | :heavy_check_mark: |          |                   |
-| [`@typescript-eslint/member-delimiter-style`](./docs/rules/member-delimiter-style.md)                     | Require a specific member delimiter style for interfaces and type literals                                                                          | :heavy_check_mark: | :wrench: |
+| [`@typescript-eslint/member-delimiter-style`](./docs/rules/member-delimiter-style.md)                     | Require a specific member delimiter style for interfaces and type literals                                                                          | :heavy_check_mark: | :wrench: |                   |
 | [`@typescript-eslint/member-naming`](./docs/rules/member-naming.md)                                       | Enforces naming conventions for class members by visibility.                                                                                        |                    |          |                   |
 | [`@typescript-eslint/member-ordering`](./docs/rules/member-ordering.md)                                   | Require a consistent member declaration order (`member-ordering` from TSLint)                                                                       |                    |          |                   |
 | [`@typescript-eslint/no-angle-bracket-type-assertion`](./docs/rules/no-angle-bracket-type-assertion.md)   | Enforces the use of `as Type` assertions instead of `<Type>` assertions (`no-angle-bracket-type-assertion` from TSLint)                             | :heavy_check_mark: |          |                   |

packages/eslint-plugin/docs/rules/func-call-spacing.md

@@ -0,0 +1,26 @@
+# require or disallow spacing between function identifiers and their invocations (func-call-spacing)
+
+When calling a function, developers may insert optional whitespace between the function’s name and the parentheses that invoke it.
+This rule requires or disallows spaces between the function name and the opening parenthesis that calls it.
+
+## Rule Details
+
+This rule extends the base [eslint/func-call-spacing](https://eslint.org/docs/rules/func-call-spacing) rule.
+It supports all options and features of the base rule.
+This version adds support for generic type parameters on function calls.
+
+## How to use
+
+```cjson
+{
+  // note you must disable the base rule as it can report incorrect errors
+  "func-call-spacing": "off",
+  "@typescript-eslint/func-call-spacing": ["error"]
+}
+```
+
+## Options
+
+See [eslint/func-call-spacing options](https://eslint.org/docs/rules/func-call-spacing#options).
+
+<sup>Taken with ❤️ [from ESLint core](https://github.com/eslint/eslint/blob/master/docs/rules/func-call-spacing.md)</sup>

packages/eslint-plugin/src/rules/func-call-spacing.ts

@@ -0,0 +1,153 @@
+import { TSESTree } from '@typescript-eslint/typescript-estree';
+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,
+    };
+  },
+});

packages/eslint-plugin/src/util/astUtils.ts

@@ -0,0 +1 @@
+export const LINEBREAK_MATCHER = /\r\n|[\r\n\u2028\u2029]/;

packages/eslint-plugin/src/util/index.ts

@@ -1,4 +1,5 @@
 export * from './applyDefault';
+export * from './astUtils';
 export * from './createRule';
 export * from './deepMerge';
 export * from './getParserServices';