All files / src ve.DiffMatchPatch.js

95.91% Statements 164/171
90.52% Branches 105/116
93.33% Functions 14/15
95.91% Lines 164/171

Press n or j to go to the next uncovered block, b, p or k for the previous block.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396                                  1x   56x   56x 56x         1x       1x 1x 1x 1x 1x       1x 1351x     1x     231x     231x     231x 40x     191x 594x 93x     98x     1x       1x 603x     1x   41x 41x 41x 41x 41x 41x                                 82x 711x 11x 11x 11x     82x                         89x   89x           89x 7x   82x                       51x                                             41x 41x 41x 41x 41x     28x         17x 15x   2x 2x               56x 56x       41x 188x 188x   188x       188x 188x   41x 41x     41x 188x 188x 1x 1x 1x 187x 61x 61x 61x   127x         41x 126x 126x 126x   48x 48x 48x 48x 48x 48x   48x     5x 5x   43x     4x   43x     2x         41x 41x     41x           43x 2x 2x   43x 4x 4x           126x         41x 143x 143x 143x 47x 96x 53x 43x 43x 1x 1x   42x 12x   42x 42x 17x   42x 42x         41x 19x   41x 20x           41x 60x 60x 60x 60x 60x 60x         60x       17x 4x 4x   4x 4x 4x 4x   1x       4x 1x 1x 1x     17x 1x   1x 1x 1x     1x 1x 1x 1x         17x       41x       41x 41x     41x     41x 110x 457x 10x     10x         41x   41x    
/*!
 * VisualEditor DiffMatchPatch implementation for linear model
 *
 * @copyright 2011-2020 VisualEditor Team and others; see http://ve.mit-license.org
 */
 
/* global diff_match_patch */
 
/**
 * DiffMatchPatch implementation
 *
 * @class
 * @extends diff_match_patch
 * @constructor
 * @param {ve.dm.HashValueStore} oldStore
 * @param {ve.dm.HashValueStore} newStore
 */
ve.DiffMatchPatch = function VeDiffMatchPatch( oldStore, newStore ) {
	// Parent constructor
	ve.DiffMatchPatch.super.call( this );
 
	this.store = oldStore.clone();
	this.store.merge( newStore );
};
 
/* Inheritance */
 
OO.inheritClass( ve.DiffMatchPatch, diff_match_patch );
 
/* Static properties */
 
ve.DiffMatchPatch.static.DIFF_DELETE = -1;
ve.DiffMatchPatch.static.DIFF_INSERT = 1;
ve.DiffMatchPatch.static.DIFF_EQUAL = 0;
ve.DiffMatchPatch.static.DIFF_CHANGE_DELETE = -2;
ve.DiffMatchPatch.static.DIFF_CHANGE_INSERT = 2;
 
/* Methods */
 
ve.DiffMatchPatch.prototype.isEqualChar = function ( a, b ) {
	return a === b || ve.dm.ElementLinearData.static.compareElements( a, b, this.store, this.store );
};
 
ve.DiffMatchPatch.prototype.isEqualString = function ( a, b ) {
	var i, l;
 
	Iif ( a === b ) {
		return true;
	}
	Iif ( a === null || b === null ) {
		return false;
	}
	if ( a.length !== b.length ) {
		return false;
	}
 
	for ( i = 0, l = a.length; i < l; i++ ) {
		if ( !this.isEqualChar( a[ i ], b[ i ] ) ) {
			return false;
		}
	}
	return true;
};
 
ve.DiffMatchPatch.prototype.charsToString = function ( chars ) {
	return chars.slice();
};
 
ve.DiffMatchPatch.prototype.getEmptyString = function () {
	return [];
};
 
ve.DiffMatchPatch.prototype.getCleanDiff = function ( oldData, newData, options ) {
	var cleanDiff, i, ilen, j,
		store = this.store,
		DIFF_DELETE = this.constructor.static.DIFF_DELETE,
		DIFF_INSERT = this.constructor.static.DIFF_INSERT,
		DIFF_EQUAL = this.constructor.static.DIFF_EQUAL,
		DIFF_CHANGE_DELETE = this.constructor.static.DIFF_CHANGE_DELETE,
		DIFF_CHANGE_INSERT = this.constructor.static.DIFF_CHANGE_INSERT;
 
	/**
	 * Remove the close elements from the linear data, to force a balanced diff.
	 *
	 * Otherwise, for example, removing the second of two consecutive comment
	 * nodes could result in a diff where [{type: '/comment'}, {type: 'comment'}]
	 * is removed, which is unbalanced.
	 *
	 * Warning: this step assumes that, within a content branch node, an element
	 * is always immediately followed by its close element.
	 *
	 * @param {Array} data Linear data
	 * @return {Array} Linear data without close elements
	 */
	function removeCloseElements( data ) {
		var i, ilen;
		for ( i = 0, ilen = data.length; i < ilen; i++ ) {
			if ( data[ i ].type && data[ i ].type[ 0 ] === '/' ) {
				data.splice( i, 1 );
				ilen--;
				i--;
			}
		}
		return data;
	}
 
	/**
	 * Get the index of the first or last wordbreak in a data array
	 *
	 * @param {Array} data Linear data
	 * @param {boolean} reversed Get the index of the last wordbreak
	 * @return {number|null} Index of the first or last wordbreak, or null if no
	 *  wordbreak was found
	 */
	function findWordbreaks( data, reversed ) {
		var offset,
			dataString = new ve.dm.DataString( data );
 
		offset = unicodeJS.wordbreak.moveBreakOffset(
			reversed ? -1 : 1,
			dataString,
			reversed ? data.length : 0
		);
 
		if ( ( reversed && offset === 0 ) || ( !reversed && offset === data.length ) ) {
			return null;
		} else {
			return offset;
		}
	}
 
	/**
	 * Determine whether there is a wordbreak at an offset
	 *
	 * @param {Array} data Linear data
	 * @param {number} offset
	 * @return {boolean} There is a wordbreak at the offset
	 */
	function isBreak( data, offset ) {
		return !!( unicodeJS.wordbreak.isBreak( new ve.dm.DataString( data ), offset ) );
	}
 
	/**
	 * The perfect diff is not always human-friendly, so clean it up.
	 * Make sure retained content spans whole words (no wordbreaks),
	 * and "de-stripe" any sequences of alternating removes and inserts
	 * (with no retains) to look like one continuous removal and one continuous
	 * insert.
	 *
	 * Additionally clean up mistakes made by the linear differ, such as removing
	 * and inserting identical content (insetead of retaining it) and removing,
	 * inserting or retaining an empty content array.
	 *
	 * @param {Array} diff Linear diff, as arrays of inserted, removed and retained
	 * content
	 * @return {Array} A human-friendlier linear diff
	 */
	function getCleanDiff( diff ) {
		var i, ilen, j, action, data, firstWordbreak, lastWordbreak,
			start, end, aItem, bItem, aAction, bAction, aData, bData,
			aAnnotations, bAnnotations, annotationChanges, attributeChanges,
			notNextStartsWithWordbreak, notPreviousEndsWithWordBreak,
			previousData = null,
			previousAction = null,
			cleanDiff = [],
			remove = [],
			insert = [];
 
		function equalUnannotated( other, element, index ) {
			return ve.dm.ElementLinearData.static.compareElementsUnannotated( element, other[ index ] );
		}
 
		function equalElements( other, element, index ) {
			// Non-elements can't be equal to other elements
			if ( !element.type || !other[ index ].type ) {
				return false;
			}
			Eif ( ve.dm.LinearData.static.isOpenElementData( element ) ) {
				return ve.dm.modelRegistry.lookup( element.type ).static.isDiffComparable( element, other[ index ], store, store );
			} else {
				// Ignore close elements
				return true;
			}
		}
 
		function isWhitespace( element ) {
			var data = Array.isArray( element ) ? element[ 0 ] : element;
			return typeof data === 'string' && !!data.match( /\s/ );
		}
 
		// Where the same data is removed and inserted, replace it with a retain
		for ( i = 0; i < diff.length; i++ ) {
			action = diff[ i ][ 0 ];
			data = diff[ i ][ 1 ];
			// Should improve on JSON.stringify
			Iif ( ( action > 0 || previousAction > 0 ) && action + previousAction === 0 && JSON.stringify( data ) === JSON.stringify( previousData ) ) {
				diff.splice( i - 1, 2, [ DIFF_EQUAL, data ] );
				i++;
			}
			previousAction = action;
			previousData = data;
		}
		previousData = null;
		previousAction = null;
 
		// Join any consecutive actions that are the same
		for ( i = 0; i < diff.length; i++ ) {
			action = diff[ i ][ 0 ];
			if ( action === previousAction ) {
				diff[ i - 1 ][ 1 ] = diff[ i - 1 ][ 1 ].concat( diff[ i ][ 1 ] );
				diff.splice( i, 1 );
				i--;
			} else if ( diff[ i ][ 1 ].length === 0 ) {
				diff.splice( i, 1 );
				i--;
				continue;
			}
			previousAction = action;
		}
 
		// Convert any retains that do not end and start with spaces into remove-
		// inserts
		for ( i = 0; i < diff.length; i++ ) {
			action = diff[ i ][ 0 ];
			data = diff[ i ][ 1 ];
			if ( action === DIFF_EQUAL ) {
 
				start = [];
				end = [];
				firstWordbreak = findWordbreaks( data, false );
				lastWordbreak = firstWordbreak === null ? null : findWordbreaks( data, true );
				notNextStartsWithWordbreak = i !== diff.length - 1 && !isBreak( data.concat( diff[ i + 1 ][ 1 ] ), data.length );
				notPreviousEndsWithWordBreak = i !== 0 && !isBreak( previousData.concat( data ), previousData.length );
 
				if ( firstWordbreak === null && ( notNextStartsWithWordbreak || notPreviousEndsWithWordBreak ) ) {
					// If there was no wordbreak, and there are no wordbreaks either side,
					// the retain should be replaced with a remove-insert
					diff.splice( i, 1, [ DIFF_DELETE, data ], [ DIFF_INSERT, data ] );
					i++;
				} else {
					if ( notNextStartsWithWordbreak ) {
						// Unless the next item starts with a wordbreak, replace the portion
						// after the last wordbreak.
						end = data.splice( lastWordbreak );
					}
					if ( notPreviousEndsWithWordBreak ) {
						// Unless the previous item ends with a word break,replace the portion
						// before the first wordbreak.
						start = data.splice( 0, firstWordbreak );
					} else {
						// Skip over close tags to ensure a balanced remove/insert
						// Word break logic should ensure that there aren't unbalanced
						// tags on the left of the remove/insert
						j = 0;
						while ( ve.dm.LinearData.static.isCloseElementData( data[ j ] ) ) {
							j++;
						}
						start = data.splice( 0, j );
					}
 
					// At this point the only portion we want to retain is what's left of
					// data (if anything; if firstWordbreak === lastWordbreak !== null, then
					// data has been spliced away completely).
					if ( start.length > 0 ) {
						diff.splice( i, 0, [ DIFF_DELETE, start ], [ DIFF_INSERT, start ] );
						i += 2;
					}
					if ( end.length > 0 ) {
						diff.splice( i + 1, 0, [ DIFF_DELETE, end ], [ DIFF_INSERT, end ] );
						i += 2;
					}
 
				}
 
			}
			previousData = data;
		}
 
		// In a sequence of -remove-insert-remove-insert- make the removes into a
		// single action and the inserts into a single action
		for ( i = 0, ilen = diff.length; i < ilen; i++ ) {
			action = diff[ i ][ 0 ];
			data = diff[ i ][ 1 ];
			if ( action === DIFF_DELETE ) {
				remove = remove.concat( data );
			} else if ( action === DIFF_INSERT ) {
				insert = insert.concat( data );
			} else Eif ( action === DIFF_EQUAL && data.length > 0 ) {
				if ( data.every( isWhitespace ) ) {
					remove = remove.concat( data );
					insert = insert.concat( data );
				} else {
					if ( remove.length > 0 ) {
						cleanDiff.push( [ DIFF_DELETE, remove ] );
					}
					remove = [];
					if ( insert.length > 0 ) {
						cleanDiff.push( [ DIFF_INSERT, insert ] );
					}
					insert = [];
					cleanDiff.push( diff[ i ] );
				}
			}
		}
 
		if ( remove.length > 0 ) {
			cleanDiff.push( [ DIFF_DELETE, remove ] );
		}
		if ( insert.length > 0 ) {
			cleanDiff.push( [ DIFF_INSERT, insert ] );
		}
 
		// Now go over any consecutive remove-inserts (also insert-removes?) and
		// if they have the same character data, or are modified content nodes,
		// make them changes instead
		for ( i = 0, ilen = cleanDiff.length - 1; i < ilen; i++ ) {
			aItem = cleanDiff[ i ];
			bItem = cleanDiff[ i + 1 ];
			aData = aItem[ 1 ];
			bData = bItem[ 1 ];
			aAction = aItem[ 0 ];
			bAction = bItem[ 0 ];
			// If they have the same length content and they are a consecutive
			// remove and insert, and they have the same content then mark the
			// old one as a change-remove (-2) and the new one as a change-insert
			// (2)
			if (
				aData.length === bData.length &&
				( ( aAction === DIFF_DELETE && bAction === DIFF_INSERT ) || ( aAction === DIFF_INSERT && bAction === DIFF_DELETE ) )
			) {
				if ( aData.every( equalUnannotated.bind( this, bData ) ) ) {
					aAnnotations = new ve.dm.ElementLinearData( store, aData ).getAnnotationsFromRange( new ve.Range( 0, aData.length ), true );
					bAnnotations = new ve.dm.ElementLinearData( store, bData ).getAnnotationsFromRange( new ve.Range( 0, bData.length ), true );
 
					annotationChanges = [];
					bAnnotations.get().forEach( function ( b ) { // eslint-disable-line no-loop-func
						var sameName = aAnnotations.getAnnotationsByName( b.name );
						if ( sameName.getLength() && !aAnnotations.containsComparable( b ) ) {
							// Annotations which have the same type, but are non-comparable, e.g. link with a different href
							annotationChanges.push( { oldAnnotation: sameName.get( 0 ), newAnnotation: b } );
						}
					} );
 
					if ( annotationChanges.length ) {
						cleanDiff[ i + 1 ].annotationChanges = annotationChanges;
						cleanDiff[ i ][ 0 ] = aAction === DIFF_DELETE ? DIFF_CHANGE_DELETE : DIFF_CHANGE_INSERT;
						cleanDiff[ i + 1 ][ 0 ] = bAction === DIFF_DELETE ? DIFF_CHANGE_DELETE : DIFF_CHANGE_INSERT;
					}
				}
				if ( aData.every( equalElements.bind( this, bData ) ) ) {
					attributeChanges = [];
					// eslint-disable-next-line no-loop-func
					bData.forEach( function ( element, i ) {
						Eif ( ve.dm.LinearData.static.isOpenElementData( element ) ) {
							attributeChanges.push( { oldAttributes: aData[ i ].attributes, newAttributes: element.attributes, index: i } );
						}
					} );
					Eif ( attributeChanges.length ) {
						cleanDiff[ i + 1 ].attributeChanges = attributeChanges;
						cleanDiff[ i ][ 0 ] = aAction === DIFF_DELETE ? DIFF_CHANGE_DELETE : DIFF_CHANGE_INSERT;
						cleanDiff[ i + 1 ][ 0 ] = bAction === DIFF_DELETE ? DIFF_CHANGE_DELETE : DIFF_CHANGE_INSERT;
					}
				}
 
				// No need to check bItem against the following item
				i += 1;
			}
		}
 
		return cleanDiff;
	}
 
	// Remove the close elements
	oldData = removeCloseElements( oldData );
	newData = removeCloseElements( newData );
 
	// Get the diff
	cleanDiff = getCleanDiff( this.diff_main( oldData, newData, options ) );
 
	// Re-insert the close elements
	for ( i = 0, ilen = cleanDiff.length; i < ilen; i++ ) {
		for ( j = 0; j < cleanDiff[ i ][ 1 ].length; j++ ) {
			if ( cleanDiff[ i ][ 1 ][ j ].type ) {
				cleanDiff[ i ][ 1 ].splice( j + 1, 0, {
					type: '/' + cleanDiff[ i ][ 1 ][ j ].type
				} );
				j++;
			}
		}
	}
 
	cleanDiff.timedOut = this.lastDiffTimedOut;
 
	return cleanDiff;
};