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Diffstat (limited to 'node_modules/webpack-sources/lib/applySourceMap.js')
| -rw-r--r-- | node_modules/webpack-sources/lib/applySourceMap.js | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/node_modules/webpack-sources/lib/applySourceMap.js b/node_modules/webpack-sources/lib/applySourceMap.js new file mode 100644 index 0000000..9696f4b --- /dev/null +++ b/node_modules/webpack-sources/lib/applySourceMap.js @@ -0,0 +1,185 @@ +/* + MIT License http://www.opensource.org/licenses/mit-license.php + Author Tobias Koppers @sokra +*/ + +"use strict"; + +var SourceNode = require("source-map").SourceNode; +var SourceMapConsumer = require("source-map").SourceMapConsumer; + +var applySourceMap = function( + sourceNode, + sourceMapConsumer, + sourceFile, + removeGeneratedCodeForSourceFile +) { + // The following notations are used to name stuff: + // Left <------------> Middle <-------------------> Right + // Input arguments: + // sourceNode - Code mapping from Left to Middle + // sourceFile - Name of a Middle file + // sourceMapConsumer - Code mapping from Middle to Right + // Variables: + // l2m m2r + // Left <-----------------------------------------> Right + // Variables: + // l2r + + var l2rResult = new SourceNode(); + var l2rOutput = []; + + var middleSourceContents = {}; + + var m2rMappingsByLine = {}; + + var rightSourceContentsSet = {}; + var rightSourceContentsLines = {}; + + // Store all mappings by generated line + sourceMapConsumer.eachMapping( + function(mapping) { + (m2rMappingsByLine[mapping.generatedLine] = + m2rMappingsByLine[mapping.generatedLine] || []).push(mapping); + }, + null, + SourceMapConsumer.GENERATED_ORDER + ); + + // Store all source contents + sourceNode.walkSourceContents(function(source, content) { + middleSourceContents["$" + source] = content; + }); + + var middleSource = middleSourceContents["$" + sourceFile]; + var middleSourceLines = middleSource ? middleSource.split("\n") : undefined; + + // Walk all left to middle mappings + sourceNode.walk(function(chunk, middleMapping) { + var source; + + // Find a mapping from middle to right + if( + middleMapping.source === sourceFile && + middleMapping.line && + m2rMappingsByLine[middleMapping.line] + ) { + var m2rBestFit; + var m2rMappings = m2rMappingsByLine[middleMapping.line]; + // Note: if this becomes a performance problem, use binary search + for(var i = 0; i < m2rMappings.length; i++) { + if(m2rMappings[i].generatedColumn <= middleMapping.column) { + m2rBestFit = m2rMappings[i]; + } + } + if(m2rBestFit) { + var allowMiddleName = false; + var middleLine; + var rightSourceContent; + var rightSourceContentLines; + var rightSource = m2rBestFit.source; + // Check if we have middle and right source for this mapping + // Then we could have an "identify" mapping + if( + middleSourceLines && + rightSource && + (middleLine = middleSourceLines[m2rBestFit.generatedLine - 1]) && + ((rightSourceContentLines = rightSourceContentsLines[rightSource]) || + (rightSourceContent = sourceMapConsumer.sourceContentFor( + rightSource, + true + ))) + ) { + if(!rightSourceContentLines) { + rightSourceContentLines = rightSourceContentsLines[ + rightSource + ] = rightSourceContent.split("\n"); + } + var rightLine = rightSourceContentLines[m2rBestFit.originalLine - 1]; + if(rightLine) { + var offset = middleMapping.column - m2rBestFit.generatedColumn; + if(offset > 0) { + var middlePart = middleLine.slice( + m2rBestFit.generatedColumn, + middleMapping.column + ); + var rightPart = rightLine.slice( + m2rBestFit.originalColumn, + m2rBestFit.originalColumn + offset + ); + if(middlePart === rightPart) { + // When original and generated code is equal we assume we have an "identity" mapping + // In this case we can offset the original position + m2rBestFit = Object.assign({}, m2rBestFit, { + originalColumn: m2rBestFit.originalColumn + offset, + generatedColumn: middleMapping.column + }); + } + } + if(!m2rBestFit.name && middleMapping.name) { + allowMiddleName = + rightLine.slice( + m2rBestFit.originalColumn, + m2rBestFit.originalColumn + middleMapping.name.length + ) === middleMapping.name; + } + } + } + + // Construct a left to right node from the found middle to right mapping + source = m2rBestFit.source; + l2rOutput.push( + new SourceNode( + m2rBestFit.originalLine, + m2rBestFit.originalColumn, + source, + chunk, + allowMiddleName ? middleMapping.name : m2rBestFit.name + ) + ); + + // Set the source contents once + if(!("$" + source in rightSourceContentsSet)) { + rightSourceContentsSet["$" + source] = true; + var sourceContent = sourceMapConsumer.sourceContentFor(source, true); + if(sourceContent) { + l2rResult.setSourceContent(source, sourceContent); + } + } + return; + } + } + + if((removeGeneratedCodeForSourceFile && middleMapping.source === sourceFile) || !middleMapping.source) { + // Construct a left to middle node with only generated code + // Because user do not want mappings to middle sources + // Or this chunk has no mapping + l2rOutput.push(chunk); + return; + } + + // Construct a left to middle node + source = middleMapping.source; + l2rOutput.push( + new SourceNode( + middleMapping.line, + middleMapping.column, + source, + chunk, + middleMapping.name + ) + ); + if("$" + source in middleSourceContents) { + if(!("$" + source in rightSourceContentsSet)) { + l2rResult.setSourceContent(source, middleSourceContents["$" + source]); + delete middleSourceContents["$" + source]; + } + } + }); + + // Put output into the resulting SourceNode + l2rResult.add(l2rOutput); + return l2rResult; +}; + +module.exports = applySourceMap; |