Implement prepareWrap and add tests for it

https://mediawiki.org/wiki/Special:Code/MediaWiki/113425

modules/ve/dm/nodes/ve.dm.DocumentNode.js

@@ -1145,6 +1145,87 @@ ve.dm.DocumentNode.prototype.prepareContentReplacement = function( range, data )
  * 
  */
 ve.dm.DocumentNode.prototype.prepareWrap = function( range, unwrapOuter, wrapOuter, unwrapEach, wrapEach ) {
+	// Function to generate arrays of closing elements in reverse order
+	function closingArray( openings ) {
+		var closings = [], i, len = openings.length;
+		for ( i = 0; i < len; i++ ) {
+			closings[closings.length] = { 'type': '/' + openings[len - i - 1].type };
+		}
+		return closings;
+	}
+	
+	// TODO sanity checks:
+	// * range.start > unwrapOuter.length
+	// * unwraps actually match
+	// * result is valid
+	
+	var tx = new ve.dm.Transaction();
+	range.normalize();
+	if ( range.start > unwrapOuter.length ) {
+		// Retain up to the first thing we're unwrapping
+		// The outer unwrapping takes place *outside*
+		// the range, so compensate for that
+		tx.pushRetain ( range.start - unwrapOuter.length );
+	}
+	
+	// Replace the opening elements for the outer unwrap&wrap
+	if ( wrapOuter.length > 0 || unwrapOuter.length > 0 ) {
+		tx.pushReplace( unwrapOuter, wrapOuter );
+	}
+	
+	if ( wrapEach.length > 0 && unwrapEach.length > 0 ) {
+		var	closingUnwrapEach = closingArray( unwrapEach ),
+			closingWrapEach = closingArray( wrapEach ),
+			depth = 0,
+			startOffset,
+			i;
+		// Visit each top-level child and wrap/unwrap it
+		// TODO figure out if we should use the tree/node functions here
+		// rather than iterating over offsets, it may or may not be faster
+		for ( i = range.start; i < range.end; i++ ) {
+			if ( this.data[offset].type === undefined ) {
+				// This is a content offset, skip
+			} else {
+				// This is a structural offset
+				if ( this.data[offset].type.charAt( 0 ) != '/' ) {
+					// This is an opening element
+					if ( depth == 0 ) {
+						// We are at the start of a top-level element
+						// Replace the opening elements
+						tx.pushReplace( unwrapEach, wrapEach );
+						// Store this offset for later
+						startOffset = i;
+					}
+					depth++;
+				} else {
+					// This is a closing element
+					depth--;
+					if ( depth == 0 ) {
+						// We are at the end of a top-level element
+						// Retain the contents of what we're wrapping
+						tx.pushRetain( i - startOffset + 1 - unwrapEach.length*2 );
+						// Replace the closing elements
+						tx.pushReplace( closingUnwrapEach, closingWrapEach );
+					}
+				}
+			}
+		}
+	} else {
+		// There is no wrapEach/unwrapEach to be done, just retain
+		// up to the end of the range
+		tx.pushRetain( range.end - range.start );
+	}
+	
+	if ( wrapOuter.length > 0 || unwrapOuter.length > 0 ) {
+		tx.pushReplace( closingArray( unwrapOuter ), closingArray( wrapOuter ) );
+	}
+	
+	// Retain up to the end of the document
+	if ( range.end < this.data.length ) {
+		tx.pushRetain( this.data.length - range.end - unwrapOuter.length );
+	}
+	
+	return tx;
 };
 
 

tests/ve/ve.dm.DocumentNode.test.js

@@ -800,3 +800,19 @@ test( 've.dm.DocumentNode.prepareInsertion', 11, function() {
 		'prepareInsertion throws exception for malformed input'
 	);
 } );
+
+test( 've.dm.DocumentNode.prepareWrap', 1, function() {
+	var documentModel = ve.dm.DocumentNode.newFromPlainObject( veTest.obj );
+	
+	// Test 1
+	deepEqual(
+		documentModel.prepareWrap( new ve.Range( 1, 4 ), [ { 'type': 'paragraph' } ], [ { 'type': 'heading', 'level': 2 } ], [], [] ).getOperations(),
+		[
+			{ 'type': 'replace', 'remove': [ { 'type': 'paragraph' } ], 'replacement': [ { 'type': 'heading', 'level': 2 } ] },
+			{ 'type': 'retain', 'length': 3 },
+			{ 'type': 'replace', 'remove': [ { 'type': '/paragraph' } ], 'replacement': [ { 'type': '/heading' } ] },
+			{ 'type': 'retain', 'length': 29 }
+		],
+		'prepareWrap changes a paragraph to a heading'
+	);
+} );

tests/ve/ve.dm.TransactionProcessor.test.js

@@ -1,6 +1,6 @@
 module( 've/dm' );
 
-test( 've.dm.TransactionProcessor', 33, function() {
+test( 've.dm.TransactionProcessor', 35, function() {
 	var documentModel = ve.dm.DocumentNode.newFromPlainObject( veTest.obj );
 
 	// FIXME: These tests shouldn't use prepareFoo() because those functions
@@ -404,4 +404,34 @@ test( 've.dm.TransactionProcessor', 33, function() {
 		],
 		'rollback restores content'
 	);
+	
+	var paragraphToHeading = documentModel.prepareWrap( new ve.Range( 1, 4 ), [ { 'type': 'paragraph' } ], [ { 'type': 'heading', 'level': 2 } ], [], [] );
+	
+	// Test 33
+	ve.dm.TransactionProcessor.commit( documentModel, paragraphToHeading );
+	deepEqual(
+		documentModel.getData( new ve.Range( 0, 5 ) ),
+		[
+			{ 'type': 'heading', 'level': 2 },
+			'a',
+			['b', { 'type': 'textStyle/bold', 'hash': '{"type":"textStyle/bold"}' }],
+			['c', { 'type': 'textStyle/italic', 'hash': '{"type":"textStyle/italic"}' }],
+			{ 'type': '/heading' }
+		],
+		'changing paragraph to heading'
+	);
+	
+	// Test 34
+	ve.dm.TransactionProcessor.rollback( documentModel, paragraphToHeading );
+	deepEqual(
+		documentModel.getData( new ve.Range( 0, 5 ) ),
+		[
+			{ 'type': 'paragraph' },
+			'a',
+			['b', { 'type': 'textStyle/bold', 'hash': '{"type":"textStyle/bold"}' }],
+			['c', { 'type': 'textStyle/italic', 'hash': '{"type":"textStyle/italic"}' }],
+			{ 'type': '/paragraph' }
+		],
+		'rollback puts paragraph back'
+	);
 } );