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Diffstat (limited to 'node_modules/jest-diff/build/diffStrings.js')
| -rw-r--r-- | node_modules/jest-diff/build/diffStrings.js | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/node_modules/jest-diff/build/diffStrings.js b/node_modules/jest-diff/build/diffStrings.js new file mode 100644 index 000000000..6961ff801 --- /dev/null +++ b/node_modules/jest-diff/build/diffStrings.js @@ -0,0 +1,145 @@ +/** + * Copyright (c) 2014, Facebook, Inc. All rights reserved. + * + * This source code is licensed under the BSD-style license found in the + * LICENSE file in the root directory of this source tree. An additional grant + * of patent rights can be found in the PATENTS file in the same directory. + * + * + */ + +'use strict'; + +const chalk = require('chalk'); +const diff = require('diff');var _require = + +require('./constants.js');const NO_DIFF_MESSAGE = _require.NO_DIFF_MESSAGE; +const DIFF_CONTEXT = 5; + + + + + + + + + + + + + + + + + +const getColor = (added, removed) => +added ? +chalk.red : +removed ? chalk.green : chalk.dim; + +const getBgColor = (added, removed) => +added ? +chalk.bgRed : +removed ? chalk.bgGreen : chalk.dim; + +const highlightTrailingWhitespace = (line, bgColor) => +line.replace(/\s+$/, bgColor('$&')); + +const getAnnotation = options => +chalk.green('- ' + (options && options.aAnnotation || 'Expected')) + '\n' + +chalk.red('+ ' + (options && options.bAnnotation || 'Received')) + '\n\n'; + +const diffLines = (a, b) => { + let isDifferent = false; + return { + diff: diff.diffLines(a, b).map(part => {const + added = part.added,removed = part.removed; + if (part.added || part.removed) { + isDifferent = true; + } + + const lines = part.value.split('\n'); + const color = getColor(added, removed); + const bgColor = getBgColor(added, removed); + + if (lines[lines.length - 1] === '') { + lines.pop(); + } + + return lines.map(line => { + const highlightedLine = highlightTrailingWhitespace(line, bgColor); + const mark = color(part.added ? '+' : part.removed ? '-' : ' '); + return mark + ' ' + color(highlightedLine) + '\n'; + }).join(''); + }).join('').trim(), + isDifferent }; + +}; + +// Only show patch marks ("@@ ... @@") if the diff is big. +// To determine this, we need to compare either the original string (a) to +// `hunk.oldLines` or a new string to `hunk.newLines`. +// If the `oldLinesCount` is greater than `hunk.oldLines` +// we can be sure that at least 1 line has been "hidden". +const shouldShowPatchMarks = +(hunk, oldLinesCount) => oldLinesCount > hunk.oldLines; + +const createPatchMark = hunk => { + const markOld = `-${hunk.oldStart},${hunk.oldLines}`; + const markNew = `+${hunk.newStart},${hunk.newLines}`; + return chalk.yellow(`@@ ${markOld} ${markNew} @@\n`); +}; + +const structuredPatch = (a, b) => { + const options = { context: DIFF_CONTEXT }; + let isDifferent = false; + // Make sure the strings end with a newline. + if (!a.endsWith('\n')) { + a += '\n'; + } + if (!b.endsWith('\n')) { + b += '\n'; + } + + const oldLinesCount = (a.match(/\n/g) || []).length; + + return { + diff: diff.structuredPatch('', '', a, b, '', '', options). + hunks.map(hunk => { + const lines = hunk.lines.map(line => { + const added = line[0] === '+'; + const removed = line[0] === '-'; + + const color = getColor(added, removed); + const bgColor = getBgColor(added, removed); + + const highlightedLine = highlightTrailingWhitespace(line, bgColor); + return color(highlightedLine) + '\n'; + }).join(''); + + isDifferent = true; + return shouldShowPatchMarks(hunk, oldLinesCount) ? + createPatchMark(hunk) + lines : + lines; + }).join('').trim(), + isDifferent }; + +}; + +function diffStrings(a, b, options) { + // `diff` uses the Myers LCS diff algorithm which runs in O(n+d^2) time + // (where "d" is the edit distance) and can get very slow for large edit + // distances. Mitigate the cost by switching to a lower-resolution diff + // whenever linebreaks are involved. + const result = options && options.expand === false ? + structuredPatch(a, b) : + diffLines(a, b); + + if (result.isDifferent) { + return getAnnotation(options) + result.diff; + } else { + return NO_DIFF_MESSAGE; + } +} + +module.exports = diffStrings;
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