]>
Commit | Line | Data |
---|---|---|
eb39fafa DC |
1 | /** |
2 | * @fileoverview Disallows multiple blank lines. | |
3 | * implementation adapted from the no-trailing-spaces rule. | |
4 | * @author Greg Cochard | |
5 | */ | |
6 | "use strict"; | |
7 | ||
8 | //------------------------------------------------------------------------------ | |
9 | // Rule Definition | |
10 | //------------------------------------------------------------------------------ | |
11 | ||
12 | module.exports = { | |
13 | meta: { | |
14 | type: "layout", | |
15 | ||
16 | docs: { | |
17 | description: "disallow multiple empty lines", | |
eb39fafa DC |
18 | recommended: false, |
19 | url: "https://eslint.org/docs/rules/no-multiple-empty-lines" | |
20 | }, | |
21 | ||
22 | fixable: "whitespace", | |
23 | ||
24 | schema: [ | |
25 | { | |
26 | type: "object", | |
27 | properties: { | |
28 | max: { | |
29 | type: "integer", | |
30 | minimum: 0 | |
31 | }, | |
32 | maxEOF: { | |
33 | type: "integer", | |
34 | minimum: 0 | |
35 | }, | |
36 | maxBOF: { | |
37 | type: "integer", | |
38 | minimum: 0 | |
39 | } | |
40 | }, | |
41 | required: ["max"], | |
42 | additionalProperties: false | |
43 | } | |
44 | ], | |
45 | ||
46 | messages: { | |
47 | blankBeginningOfFile: "Too many blank lines at the beginning of file. Max of {{max}} allowed.", | |
48 | blankEndOfFile: "Too many blank lines at the end of file. Max of {{max}} allowed.", | |
49 | consecutiveBlank: "More than {{max}} blank {{pluralizedLines}} not allowed." | |
50 | } | |
51 | }, | |
52 | ||
53 | create(context) { | |
54 | ||
55 | // Use options.max or 2 as default | |
56 | let max = 2, | |
57 | maxEOF = max, | |
58 | maxBOF = max; | |
59 | ||
60 | if (context.options.length) { | |
61 | max = context.options[0].max; | |
62 | maxEOF = typeof context.options[0].maxEOF !== "undefined" ? context.options[0].maxEOF : max; | |
63 | maxBOF = typeof context.options[0].maxBOF !== "undefined" ? context.options[0].maxBOF : max; | |
64 | } | |
65 | ||
66 | const sourceCode = context.getSourceCode(); | |
67 | ||
68 | // Swallow the final newline, as some editors add it automatically and we don't want it to cause an issue | |
69 | const allLines = sourceCode.lines[sourceCode.lines.length - 1] === "" ? sourceCode.lines.slice(0, -1) : sourceCode.lines; | |
70 | const templateLiteralLines = new Set(); | |
71 | ||
72 | //-------------------------------------------------------------------------- | |
73 | // Public | |
74 | //-------------------------------------------------------------------------- | |
75 | ||
76 | return { | |
77 | TemplateLiteral(node) { | |
78 | node.quasis.forEach(literalPart => { | |
79 | ||
80 | // Empty lines have a semantic meaning if they're inside template literals. Don't count these as empty lines. | |
81 | for (let ignoredLine = literalPart.loc.start.line; ignoredLine < literalPart.loc.end.line; ignoredLine++) { | |
82 | templateLiteralLines.add(ignoredLine); | |
83 | } | |
84 | }); | |
85 | }, | |
86 | "Program:exit"(node) { | |
87 | return allLines | |
88 | ||
89 | // Given a list of lines, first get a list of line numbers that are non-empty. | |
90 | .reduce((nonEmptyLineNumbers, line, index) => { | |
91 | if (line.trim() || templateLiteralLines.has(index + 1)) { | |
92 | nonEmptyLineNumbers.push(index + 1); | |
93 | } | |
94 | return nonEmptyLineNumbers; | |
95 | }, []) | |
96 | ||
97 | // Add a value at the end to allow trailing empty lines to be checked. | |
98 | .concat(allLines.length + 1) | |
99 | ||
100 | // Given two line numbers of non-empty lines, report the lines between if the difference is too large. | |
101 | .reduce((lastLineNumber, lineNumber) => { | |
102 | let messageId, maxAllowed; | |
103 | ||
104 | if (lastLineNumber === 0) { | |
105 | messageId = "blankBeginningOfFile"; | |
106 | maxAllowed = maxBOF; | |
107 | } else if (lineNumber === allLines.length + 1) { | |
108 | messageId = "blankEndOfFile"; | |
109 | maxAllowed = maxEOF; | |
110 | } else { | |
111 | messageId = "consecutiveBlank"; | |
112 | maxAllowed = max; | |
113 | } | |
114 | ||
115 | if (lineNumber - lastLineNumber - 1 > maxAllowed) { | |
116 | context.report({ | |
117 | node, | |
118 | loc: { | |
119 | start: { line: lastLineNumber + maxAllowed + 1, column: 0 }, | |
120 | end: { line: lineNumber, column: 0 } | |
121 | }, | |
122 | messageId, | |
123 | data: { | |
124 | max: maxAllowed, | |
125 | pluralizedLines: maxAllowed === 1 ? "line" : "lines" | |
126 | }, | |
127 | fix(fixer) { | |
128 | const rangeStart = sourceCode.getIndexFromLoc({ line: lastLineNumber + 1, column: 0 }); | |
129 | ||
130 | /* | |
131 | * The end of the removal range is usually the start index of the next line. | |
132 | * However, at the end of the file there is no next line, so the end of the | |
133 | * range is just the length of the text. | |
134 | */ | |
135 | const lineNumberAfterRemovedLines = lineNumber - maxAllowed; | |
136 | const rangeEnd = lineNumberAfterRemovedLines <= allLines.length | |
137 | ? sourceCode.getIndexFromLoc({ line: lineNumberAfterRemovedLines, column: 0 }) | |
138 | : sourceCode.text.length; | |
139 | ||
140 | return fixer.removeRange([rangeStart, rangeEnd]); | |
141 | } | |
142 | }); | |
143 | } | |
144 | ||
145 | return lineNumber; | |
146 | }, 0); | |
147 | } | |
148 | }; | |
149 | } | |
150 | }; |