apply.js 13 KB

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  1. "use strict";
  2. Object.defineProperty(exports, "__esModule", { value: true });
  3. exports.applyPatch = applyPatch;
  4. exports.applyPatches = applyPatches;
  5. var string_js_1 = require("../util/string.js");
  6. var line_endings_js_1 = require("./line-endings.js");
  7. var parse_js_1 = require("./parse.js");
  8. var distance_iterator_js_1 = require("../util/distance-iterator.js");
  9. /**
  10. * attempts to apply a unified diff patch.
  11. *
  12. * Hunks are applied first to last.
  13. * `applyPatch` first tries to apply the first hunk at the line number specified in the hunk header, and with all context lines matching exactly.
  14. * If that fails, it tries scanning backwards and forwards, one line at a time, to find a place to apply the hunk where the context lines match exactly.
  15. * If that still fails, and `fuzzFactor` is greater than zero, it increments the maximum number of mismatches (missing, extra, or changed context lines) that there can be between the hunk context and a region where we are trying to apply the patch such that the hunk will still be considered to match.
  16. * Regardless of `fuzzFactor`, lines to be deleted in the hunk *must* be present for a hunk to match, and the context lines *immediately* before and after an insertion must match exactly.
  17. *
  18. * Once a hunk is successfully fitted, the process begins again with the next hunk.
  19. * Regardless of `fuzzFactor`, later hunks must be applied later in the file than earlier hunks.
  20. *
  21. * If a hunk cannot be successfully fitted *anywhere* with fewer than `fuzzFactor` mismatches, `applyPatch` fails and returns `false`.
  22. *
  23. * If a hunk is successfully fitted but not at the line number specified by the hunk header, all subsequent hunks have their target line number adjusted accordingly.
  24. * (e.g. if the first hunk is applied 10 lines below where the hunk header said it should fit, `applyPatch` will *start* looking for somewhere to apply the second hunk 10 lines below where its hunk header says it goes.)
  25. *
  26. * If the patch was applied successfully, returns a string containing the patched text.
  27. * If the patch could not be applied (because some hunks in the patch couldn't be fitted to the text in `source`), `applyPatch` returns false.
  28. *
  29. * @param patch a string diff or the output from the `parsePatch` or `structuredPatch` methods.
  30. */
  31. function applyPatch(source, patch, options) {
  32. if (options === void 0) { options = {}; }
  33. var patches;
  34. if (typeof patch === 'string') {
  35. patches = (0, parse_js_1.parsePatch)(patch);
  36. }
  37. else if (Array.isArray(patch)) {
  38. patches = patch;
  39. }
  40. else {
  41. patches = [patch];
  42. }
  43. if (patches.length > 1) {
  44. throw new Error('applyPatch only works with a single input.');
  45. }
  46. return applyStructuredPatch(source, patches[0], options);
  47. }
  48. function applyStructuredPatch(source, patch, options) {
  49. if (options === void 0) { options = {}; }
  50. if (options.autoConvertLineEndings || options.autoConvertLineEndings == null) {
  51. if ((0, string_js_1.hasOnlyWinLineEndings)(source) && (0, line_endings_js_1.isUnix)(patch)) {
  52. patch = (0, line_endings_js_1.unixToWin)(patch);
  53. }
  54. else if ((0, string_js_1.hasOnlyUnixLineEndings)(source) && (0, line_endings_js_1.isWin)(patch)) {
  55. patch = (0, line_endings_js_1.winToUnix)(patch);
  56. }
  57. }
  58. // Apply the diff to the input
  59. var lines = source.split('\n'), hunks = patch.hunks, compareLine = options.compareLine || (function (lineNumber, line, operation, patchContent) { return line === patchContent; }), fuzzFactor = options.fuzzFactor || 0;
  60. var minLine = 0;
  61. if (fuzzFactor < 0 || !Number.isInteger(fuzzFactor)) {
  62. throw new Error('fuzzFactor must be a non-negative integer');
  63. }
  64. // Special case for empty patch.
  65. if (!hunks.length) {
  66. return source;
  67. }
  68. // Before anything else, handle EOFNL insertion/removal. If the patch tells us to make a change
  69. // to the EOFNL that is redundant/impossible - i.e. to remove a newline that's not there, or add a
  70. // newline that already exists - then we either return false and fail to apply the patch (if
  71. // fuzzFactor is 0) or simply ignore the problem and do nothing (if fuzzFactor is >0).
  72. // If we do need to remove/add a newline at EOF, this will always be in the final hunk:
  73. var prevLine = '', removeEOFNL = false, addEOFNL = false;
  74. for (var i = 0; i < hunks[hunks.length - 1].lines.length; i++) {
  75. var line = hunks[hunks.length - 1].lines[i];
  76. if (line[0] == '\\') {
  77. if (prevLine[0] == '+') {
  78. removeEOFNL = true;
  79. }
  80. else if (prevLine[0] == '-') {
  81. addEOFNL = true;
  82. }
  83. }
  84. prevLine = line;
  85. }
  86. if (removeEOFNL) {
  87. if (addEOFNL) {
  88. // This means the final line gets changed but doesn't have a trailing newline in either the
  89. // original or patched version. In that case, we do nothing if fuzzFactor > 0, and if
  90. // fuzzFactor is 0, we simply validate that the source file has no trailing newline.
  91. if (!fuzzFactor && lines[lines.length - 1] == '') {
  92. return false;
  93. }
  94. }
  95. else if (lines[lines.length - 1] == '') {
  96. lines.pop();
  97. }
  98. else if (!fuzzFactor) {
  99. return false;
  100. }
  101. }
  102. else if (addEOFNL) {
  103. if (lines[lines.length - 1] != '') {
  104. lines.push('');
  105. }
  106. else if (!fuzzFactor) {
  107. return false;
  108. }
  109. }
  110. /**
  111. * Checks if the hunk can be made to fit at the provided location with at most `maxErrors`
  112. * insertions, substitutions, or deletions, while ensuring also that:
  113. * - lines deleted in the hunk match exactly, and
  114. * - wherever an insertion operation or block of insertion operations appears in the hunk, the
  115. * immediately preceding and following lines of context match exactly
  116. *
  117. * `toPos` should be set such that lines[toPos] is meant to match hunkLines[0].
  118. *
  119. * If the hunk can be applied, returns an object with properties `oldLineLastI` and
  120. * `replacementLines`. Otherwise, returns null.
  121. */
  122. function applyHunk(hunkLines, toPos, maxErrors, hunkLinesI, lastContextLineMatched, patchedLines, patchedLinesLength) {
  123. if (hunkLinesI === void 0) { hunkLinesI = 0; }
  124. if (lastContextLineMatched === void 0) { lastContextLineMatched = true; }
  125. if (patchedLines === void 0) { patchedLines = []; }
  126. if (patchedLinesLength === void 0) { patchedLinesLength = 0; }
  127. var nConsecutiveOldContextLines = 0;
  128. var nextContextLineMustMatch = false;
  129. for (; hunkLinesI < hunkLines.length; hunkLinesI++) {
  130. var hunkLine = hunkLines[hunkLinesI], operation = (hunkLine.length > 0 ? hunkLine[0] : ' '), content = (hunkLine.length > 0 ? hunkLine.substr(1) : hunkLine);
  131. if (operation === '-') {
  132. if (compareLine(toPos + 1, lines[toPos], operation, content)) {
  133. toPos++;
  134. nConsecutiveOldContextLines = 0;
  135. }
  136. else {
  137. if (!maxErrors || lines[toPos] == null) {
  138. return null;
  139. }
  140. patchedLines[patchedLinesLength] = lines[toPos];
  141. return applyHunk(hunkLines, toPos + 1, maxErrors - 1, hunkLinesI, false, patchedLines, patchedLinesLength + 1);
  142. }
  143. }
  144. if (operation === '+') {
  145. if (!lastContextLineMatched) {
  146. return null;
  147. }
  148. patchedLines[patchedLinesLength] = content;
  149. patchedLinesLength++;
  150. nConsecutiveOldContextLines = 0;
  151. nextContextLineMustMatch = true;
  152. }
  153. if (operation === ' ') {
  154. nConsecutiveOldContextLines++;
  155. patchedLines[patchedLinesLength] = lines[toPos];
  156. if (compareLine(toPos + 1, lines[toPos], operation, content)) {
  157. patchedLinesLength++;
  158. lastContextLineMatched = true;
  159. nextContextLineMustMatch = false;
  160. toPos++;
  161. }
  162. else {
  163. if (nextContextLineMustMatch || !maxErrors) {
  164. return null;
  165. }
  166. // Consider 3 possibilities in sequence:
  167. // 1. lines contains a *substitution* not included in the patch context, or
  168. // 2. lines contains an *insertion* not included in the patch context, or
  169. // 3. lines contains a *deletion* not included in the patch context
  170. // The first two options are of course only possible if the line from lines is non-null -
  171. // i.e. only option 3 is possible if we've overrun the end of the old file.
  172. return (lines[toPos] && (applyHunk(hunkLines, toPos + 1, maxErrors - 1, hunkLinesI + 1, false, patchedLines, patchedLinesLength + 1) || applyHunk(hunkLines, toPos + 1, maxErrors - 1, hunkLinesI, false, patchedLines, patchedLinesLength + 1)) || applyHunk(hunkLines, toPos, maxErrors - 1, hunkLinesI + 1, false, patchedLines, patchedLinesLength));
  173. }
  174. }
  175. }
  176. // Before returning, trim any unmodified context lines off the end of patchedLines and reduce
  177. // toPos (and thus oldLineLastI) accordingly. This allows later hunks to be applied to a region
  178. // that starts in this hunk's trailing context.
  179. patchedLinesLength -= nConsecutiveOldContextLines;
  180. toPos -= nConsecutiveOldContextLines;
  181. patchedLines.length = patchedLinesLength;
  182. return {
  183. patchedLines: patchedLines,
  184. oldLineLastI: toPos - 1
  185. };
  186. }
  187. var resultLines = [];
  188. // Search best fit offsets for each hunk based on the previous ones
  189. var prevHunkOffset = 0;
  190. for (var i = 0; i < hunks.length; i++) {
  191. var hunk = hunks[i];
  192. var hunkResult = void 0;
  193. var maxLine = lines.length - hunk.oldLines + fuzzFactor;
  194. var toPos = void 0;
  195. for (var maxErrors = 0; maxErrors <= fuzzFactor; maxErrors++) {
  196. toPos = hunk.oldStart + prevHunkOffset - 1;
  197. var iterator = (0, distance_iterator_js_1.default)(toPos, minLine, maxLine);
  198. for (; toPos !== undefined; toPos = iterator()) {
  199. hunkResult = applyHunk(hunk.lines, toPos, maxErrors);
  200. if (hunkResult) {
  201. break;
  202. }
  203. }
  204. if (hunkResult) {
  205. break;
  206. }
  207. }
  208. if (!hunkResult) {
  209. return false;
  210. }
  211. // Copy everything from the end of where we applied the last hunk to the start of this hunk
  212. for (var i_1 = minLine; i_1 < toPos; i_1++) {
  213. resultLines.push(lines[i_1]);
  214. }
  215. // Add the lines produced by applying the hunk:
  216. for (var i_2 = 0; i_2 < hunkResult.patchedLines.length; i_2++) {
  217. var line = hunkResult.patchedLines[i_2];
  218. resultLines.push(line);
  219. }
  220. // Set lower text limit to end of the current hunk, so next ones don't try
  221. // to fit over already patched text
  222. minLine = hunkResult.oldLineLastI + 1;
  223. // Note the offset between where the patch said the hunk should've applied and where we
  224. // applied it, so we can adjust future hunks accordingly:
  225. prevHunkOffset = toPos + 1 - hunk.oldStart;
  226. }
  227. // Copy over the rest of the lines from the old text
  228. for (var i = minLine; i < lines.length; i++) {
  229. resultLines.push(lines[i]);
  230. }
  231. return resultLines.join('\n');
  232. }
  233. /**
  234. * applies one or more patches.
  235. *
  236. * `patch` may be either an array of structured patch objects, or a string representing a patch in unified diff format (which may patch one or more files).
  237. *
  238. * This method will iterate over the contents of the patch and apply to data provided through callbacks. The general flow for each patch index is:
  239. *
  240. * - `options.loadFile(index, callback)` is called. The caller should then load the contents of the file and then pass that to the `callback(err, data)` callback. Passing an `err` will terminate further patch execution.
  241. * - `options.patched(index, content, callback)` is called once the patch has been applied. `content` will be the return value from `applyPatch`. When it's ready, the caller should call `callback(err)` callback. Passing an `err` will terminate further patch execution.
  242. *
  243. * Once all patches have been applied or an error occurs, the `options.complete(err)` callback is made.
  244. */
  245. function applyPatches(uniDiff, options) {
  246. var spDiff = typeof uniDiff === 'string' ? (0, parse_js_1.parsePatch)(uniDiff) : uniDiff;
  247. var currentIndex = 0;
  248. function processIndex() {
  249. var index = spDiff[currentIndex++];
  250. if (!index) {
  251. return options.complete();
  252. }
  253. options.loadFile(index, function (err, data) {
  254. if (err) {
  255. return options.complete(err);
  256. }
  257. var updatedContent = applyPatch(data, index, options);
  258. options.patched(index, updatedContent, function (err) {
  259. if (err) {
  260. return options.complete(err);
  261. }
  262. processIndex();
  263. });
  264. });
  265. }
  266. processIndex();
  267. }