2 * @fileoverview A rule to disallow or enforce spaces inside of single line blocks.
3 * @author Toru Nagashima
8 const util = require("./utils/ast-utils");
10 //------------------------------------------------------------------------------
12 //------------------------------------------------------------------------------
19 description: "disallow or enforce spaces inside of blocks after opening block and before closing block",
20 category: "Stylistic Issues",
22 url: "https://eslint.org/docs/rules/block-spacing"
25 fixable: "whitespace",
28 { enum: ["always", "never"] }
32 missing: "Requires a space {{location}} '{{token}}'.",
33 extra: "Unexpected space(s) {{location}} '{{token}}'."
38 const always = (context.options[0] !== "never"),
39 messageId = always ? "missing" : "extra",
40 sourceCode = context.getSourceCode();
43 * Gets the open brace token from a given node.
44 * @param {ASTNode} node A BlockStatement/SwitchStatement node to get.
45 * @returns {Token} The token of the open brace.
47 function getOpenBrace(node) {
48 if (node.type === "SwitchStatement") {
49 if (node.cases.length > 0) {
50 return sourceCode.getTokenBefore(node.cases[0]);
52 return sourceCode.getLastToken(node, 1);
54 return sourceCode.getFirstToken(node);
58 * Checks whether or not:
59 * - given tokens are on same line.
60 * - there is/isn't a space between given tokens.
61 * @param {Token} left A token to check.
62 * @param {Token} right The token which is next to `left`.
64 * When the option is `"always"`, `true` if there are one or more spaces between given tokens.
65 * When the option is `"never"`, `true` if there are not any spaces between given tokens.
66 * If given tokens are not on same line, it's always `true`.
68 function isValid(left, right) {
70 !util.isTokenOnSameLine(left, right) ||
71 sourceCode.isSpaceBetweenTokens(left, right) === always
76 * Reports invalid spacing style inside braces.
77 * @param {ASTNode} node A BlockStatement/SwitchStatement node to get.
80 function checkSpacingInsideBraces(node) {
82 // Gets braces and the first/last token of content.
83 const openBrace = getOpenBrace(node);
84 const closeBrace = sourceCode.getLastToken(node);
85 const firstToken = sourceCode.getTokenAfter(openBrace, { includeComments: true });
86 const lastToken = sourceCode.getTokenBefore(closeBrace, { includeComments: true });
88 // Skip if the node is invalid or empty.
89 if (openBrace.type !== "Punctuator" ||
90 openBrace.value !== "{" ||
91 closeBrace.type !== "Punctuator" ||
92 closeBrace.value !== "}" ||
93 firstToken === closeBrace
98 // Skip line comments for option never
99 if (!always && firstToken.type === "Line") {
104 if (!isValid(openBrace, firstToken)) {
105 let loc = openBrace.loc;
107 if (messageId === "extra") {
109 start: openBrace.loc.end,
110 end: firstToken.loc.start
120 token: openBrace.value
124 return fixer.insertTextBefore(firstToken, " ");
127 return fixer.removeRange([openBrace.range[1], firstToken.range[0]]);
131 if (!isValid(lastToken, closeBrace)) {
132 let loc = closeBrace.loc;
134 if (messageId === "extra") {
136 start: lastToken.loc.end,
137 end: closeBrace.loc.start
146 token: closeBrace.value
150 return fixer.insertTextAfter(lastToken, " ");
153 return fixer.removeRange([lastToken.range[1], closeBrace.range[0]]);
160 BlockStatement: checkSpacingInsideBraces,
161 SwitchStatement: checkSpacingInsideBraces