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git.proxmox.com Git - pve-eslint.git/blob - eslint/lib/rules/newline-before-return.js
2 * @fileoverview Rule to require newlines before `return` statement
4 * @deprecated in ESLint v4.0.0
8 //------------------------------------------------------------------------------
10 //------------------------------------------------------------------------------
12 /** @type {import('../shared/types').Rule} */
18 description
: "Require an empty line before `return` statements",
20 url
: "https://eslint.org/docs/rules/newline-before-return"
23 fixable
: "whitespace",
26 expected
: "Expected newline before return statement."
30 replacedBy
: ["padding-line-between-statements"]
34 const sourceCode
= context
.getSourceCode();
36 //--------------------------------------------------------------------------
38 //--------------------------------------------------------------------------
41 * Tests whether node is preceded by supplied tokens
42 * @param {ASTNode} node node to check
43 * @param {Array} testTokens array of tokens to test against
44 * @returns {boolean} Whether or not the node is preceded by one of the supplied tokens
47 function isPrecededByTokens(node
, testTokens
) {
48 const tokenBefore
= sourceCode
.getTokenBefore(node
);
50 return testTokens
.includes(tokenBefore
.value
);
54 * Checks whether node is the first node after statement or in block
55 * @param {ASTNode} node node to check
56 * @returns {boolean} Whether or not the node is the first node after statement or in block
59 function isFirstNode(node
) {
60 const parentType
= node
.parent
.type
;
62 if (node
.parent
.body
) {
63 return Array
.isArray(node
.parent
.body
)
64 ? node
.parent
.body
[0] === node
65 : node
.parent
.body
=== node
;
68 if (parentType
=== "IfStatement") {
69 return isPrecededByTokens(node
, ["else", ")"]);
71 if (parentType
=== "DoWhileStatement") {
72 return isPrecededByTokens(node
, ["do"]);
74 if (parentType
=== "SwitchCase") {
75 return isPrecededByTokens(node
, [":"]);
77 return isPrecededByTokens(node
, [")"]);
82 * Returns the number of lines of comments that precede the node
83 * @param {ASTNode} node node to check for overlapping comments
84 * @param {number} lineNumTokenBefore line number of previous token, to check for overlapping comments
85 * @returns {number} Number of lines of comments that precede the node
88 function calcCommentLines(node
, lineNumTokenBefore
) {
89 const comments
= sourceCode
.getCommentsBefore(node
);
90 let numLinesComments
= 0;
92 if (!comments
.length
) {
93 return numLinesComments
;
96 comments
.forEach(comment
=> {
99 if (comment
.type
=== "Block") {
100 numLinesComments
+= comment
.loc
.end
.line
- comment
.loc
.start
.line
;
103 // avoid counting lines with inline comments twice
104 if (comment
.loc
.start
.line
=== lineNumTokenBefore
) {
108 if (comment
.loc
.end
.line
=== node
.loc
.start
.line
) {
113 return numLinesComments
;
117 * Returns the line number of the token before the node that is passed in as an argument
118 * @param {ASTNode} node The node to use as the start of the calculation
119 * @returns {number} Line number of the token before `node`
122 function getLineNumberOfTokenBefore(node
) {
123 const tokenBefore
= sourceCode
.getTokenBefore(node
);
124 let lineNumTokenBefore
;
127 * Global return (at the beginning of a script) is a special case.
128 * If there is no token before `return`, then we expect no line
129 * break before the return. Comments are allowed to occupy lines
130 * before the global return, just no blank lines.
131 * Setting lineNumTokenBefore to zero in that case results in the
135 lineNumTokenBefore
= tokenBefore
.loc
.end
.line
;
137 lineNumTokenBefore
= 0; // global return at beginning of script
140 return lineNumTokenBefore
;
144 * Checks whether node is preceded by a newline
145 * @param {ASTNode} node node to check
146 * @returns {boolean} Whether or not the node is preceded by a newline
149 function hasNewlineBefore(node
) {
150 const lineNumNode
= node
.loc
.start
.line
;
151 const lineNumTokenBefore
= getLineNumberOfTokenBefore(node
);
152 const commentLines
= calcCommentLines(node
, lineNumTokenBefore
);
154 return (lineNumNode
- lineNumTokenBefore
- commentLines
) > 1;
158 * Checks whether it is safe to apply a fix to a given return statement.
160 * The fix is not considered safe if the given return statement has leading comments,
161 * as we cannot safely determine if the newline should be added before or after the comments.
162 * For more information, see: https://github.com/eslint/eslint/issues/5958#issuecomment-222767211
163 * @param {ASTNode} node The return statement node to check.
164 * @returns {boolean} `true` if it can fix the node.
167 function canFix(node
) {
168 const leadingComments
= sourceCode
.getCommentsBefore(node
);
169 const lastLeadingComment
= leadingComments
[leadingComments
.length
- 1];
170 const tokenBefore
= sourceCode
.getTokenBefore(node
);
172 if (leadingComments
.length
=== 0) {
177 * if the last leading comment ends in the same line as the previous token and
178 * does not share a line with the `return` node, we can consider it safe to fix.
185 if (lastLeadingComment
.loc
.end
.line
=== tokenBefore
.loc
.end
.line
&&
186 lastLeadingComment
.loc
.end
.line
!== node
.loc
.start
.line
) {
193 //--------------------------------------------------------------------------
195 //--------------------------------------------------------------------------
198 ReturnStatement(node
) {
199 if (!isFirstNode(node
) && !hasNewlineBefore(node
)) {
202 messageId
: "expected",
205 const tokenBefore
= sourceCode
.getTokenBefore(node
);
206 const newlines
= node
.loc
.start
.line
=== tokenBefore
.loc
.end
.line
? "\n\n" : "\n";
208 return fixer
.insertTextBefore(node
, newlines
);