2 * @fileoverview Validates spacing before and after semicolon
3 * @author Mathias Schreck
8 const astUtils
= require("./utils/ast-utils");
10 //------------------------------------------------------------------------------
12 //------------------------------------------------------------------------------
19 description
: "enforce consistent spacing before and after semicolons",
20 category
: "Stylistic Issues",
22 url
: "https://eslint.org/docs/rules/semi-spacing"
25 fixable
: "whitespace",
40 additionalProperties
: false
45 unexpectedWhitespaceBefore
: "Unexpected whitespace before semicolon.",
46 unexpectedWhitespaceAfter
: "Unexpected whitespace after semicolon.",
47 missingWhitespaceBefore
: "Missing whitespace before semicolon.",
48 missingWhitespaceAfter
: "Missing whitespace after semicolon."
54 const config
= context
.options
[0],
55 sourceCode
= context
.getSourceCode();
56 let requireSpaceBefore
= false,
57 requireSpaceAfter
= true;
59 if (typeof config
=== "object") {
60 requireSpaceBefore
= config
.before
;
61 requireSpaceAfter
= config
.after
;
65 * Checks if a given token has leading whitespace.
66 * @param {Object} token The token to check.
67 * @returns {boolean} True if the given token has leading space, false if not.
69 function hasLeadingSpace(token
) {
70 const tokenBefore
= sourceCode
.getTokenBefore(token
);
72 return tokenBefore
&& astUtils
.isTokenOnSameLine(tokenBefore
, token
) && sourceCode
.isSpaceBetweenTokens(tokenBefore
, token
);
76 * Checks if a given token has trailing whitespace.
77 * @param {Object} token The token to check.
78 * @returns {boolean} True if the given token has trailing space, false if not.
80 function hasTrailingSpace(token
) {
81 const tokenAfter
= sourceCode
.getTokenAfter(token
);
83 return tokenAfter
&& astUtils
.isTokenOnSameLine(token
, tokenAfter
) && sourceCode
.isSpaceBetweenTokens(token
, tokenAfter
);
87 * Checks if the given token is the last token in its line.
88 * @param {Token} token The token to check.
89 * @returns {boolean} Whether or not the token is the last in its line.
91 function isLastTokenInCurrentLine(token
) {
92 const tokenAfter
= sourceCode
.getTokenAfter(token
);
94 return !(tokenAfter
&& astUtils
.isTokenOnSameLine(token
, tokenAfter
));
98 * Checks if the given token is the first token in its line
99 * @param {Token} token The token to check.
100 * @returns {boolean} Whether or not the token is the first in its line.
102 function isFirstTokenInCurrentLine(token
) {
103 const tokenBefore
= sourceCode
.getTokenBefore(token
);
105 return !(tokenBefore
&& astUtils
.isTokenOnSameLine(token
, tokenBefore
));
109 * Checks if the next token of a given token is a closing parenthesis.
110 * @param {Token} token The token to check.
111 * @returns {boolean} Whether or not the next token of a given token is a closing parenthesis.
113 function isBeforeClosingParen(token
) {
114 const nextToken
= sourceCode
.getTokenAfter(token
);
116 return (nextToken
&& astUtils
.isClosingBraceToken(nextToken
) || astUtils
.isClosingParenToken(nextToken
));
120 * Report location example :
122 * for unexpected space `before`
127 * for unexpected space `after`
129 * var a = 'b'; c = 10;
132 * Reports if the given token has invalid spacing.
133 * @param {Token} token The semicolon token to check.
134 * @param {ASTNode} node The corresponding node of the token.
137 function checkSemicolonSpacing(token
, node
) {
138 if (astUtils
.isSemicolonToken(token
)) {
139 if (hasLeadingSpace(token
)) {
140 if (!requireSpaceBefore
) {
141 const tokenBefore
= sourceCode
.getTokenBefore(token
);
143 start
: tokenBefore
.loc
.end
,
150 messageId
: "unexpectedWhitespaceBefore",
153 return fixer
.removeRange([tokenBefore
.range
[1], token
.range
[0]]);
158 if (requireSpaceBefore
) {
159 const loc
= token
.loc
;
164 messageId
: "missingWhitespaceBefore",
166 return fixer
.insertTextBefore(token
, " ");
172 if (!isFirstTokenInCurrentLine(token
) && !isLastTokenInCurrentLine(token
) && !isBeforeClosingParen(token
)) {
173 if (hasTrailingSpace(token
)) {
174 if (!requireSpaceAfter
) {
175 const tokenAfter
= sourceCode
.getTokenAfter(token
);
177 start
: token
.loc
.end
,
178 end
: tokenAfter
.loc
.start
184 messageId
: "unexpectedWhitespaceAfter",
187 return fixer
.removeRange([token
.range
[1], tokenAfter
.range
[0]]);
192 if (requireSpaceAfter
) {
193 const loc
= token
.loc
;
198 messageId
: "missingWhitespaceAfter",
200 return fixer
.insertTextAfter(token
, " ");
210 * Checks the spacing of the semicolon with the assumption that the last token is the semicolon.
211 * @param {ASTNode} node The node to check.
214 function checkNode(node
) {
215 const token
= sourceCode
.getLastToken(node
);
217 checkSemicolonSpacing(token
, node
);
221 VariableDeclaration
: checkNode
,
222 ExpressionStatement
: checkNode
,
223 BreakStatement
: checkNode
,
224 ContinueStatement
: checkNode
,
225 DebuggerStatement
: checkNode
,
226 DoWhileStatement
: checkNode
,
227 ReturnStatement
: checkNode
,
228 ThrowStatement
: checkNode
,
229 ImportDeclaration
: checkNode
,
230 ExportNamedDeclaration
: checkNode
,
231 ExportAllDeclaration
: checkNode
,
232 ExportDefaultDeclaration
: checkNode
,
235 checkSemicolonSpacing(sourceCode
.getTokenAfter(node
.init
), node
);
239 checkSemicolonSpacing(sourceCode
.getTokenAfter(node
.test
), node
);