[test] all tests pass again

lib/data-utils.js

@@ -2,6 +2,7 @@
 //
 // data utilities
 //
+var helpers = require('../common/helpers');
 
 module.exports = utils = {};
 

lib/filediff.js

@@ -0,0 +1,159 @@
+
+var helpers = require('../common/helpers');
+var Diff = require('../common/diff');
+
+module.exports = function FileDiff(file1, file2, options) {
+
+  if (!(this instanceof FileDiff)) {
+    return new FileDiff(file1, file2, options);
+  }
+
+  this.lines1 = file1.split("\n");
+  this.lines2 = file2.split("\n");
+  this.diffChunks = Diff.createPatch(this.lines1, this.lines2);
+
+  var MAX_LINE_CHARS = 140;
+  var options = options || {};
+  this.contextLength = options.context || 3;
+
+  this.toInfo = function() {
+
+    if (file1 === "") {
+
+      var infoChunk = { offset: 1, lines:[] };
+
+      helpers.each(this.lines2, function(line, i) {
+        infoChunk.lines.push({
+          oldIndex: null,
+          newIndex: (i + 1),
+          line: line,
+          type:"added"
+        });
+      });
+
+      return [infoChunk];
+    }
+    if (file2 === "") {
+
+      var infoChunk = { offset: 1, lines:[] };
+
+      helpers.each(this.lines1, function(line, i) {
+        infoChunk.lines.push({
+          oldIndex: (i + 1),
+          newIndex: null,
+          line: line,
+          type:"removed"
+        });
+      });
+
+      return [infoChunk];
+    }
+
+    var infos = [];
+    var diff = this;
+    var totalAdded = 0;
+    var totalRemoved = 0;
+    var lastInfoChunk = null;
+    var infoChunk = null;
+
+    helpers.each(this.diffChunks, function(chunk) {
+
+      var removed = chunk.file1;
+      var added   = chunk.file2;
+
+      infoChunk = null;
+
+      var removeContext = null;
+      var overlapLength = null;
+      var lastLineNewIndex = null;
+
+      if (lastInfoChunk) {
+
+        var lastLine = lastInfoChunk.lines[lastInfoChunk.lines.length - 1];
+
+        if (lastLine.oldIndex >= Math.max(removed.offset - diff.contextLength, 0)) {
+
+          infoChunk = lastInfoChunk;
+          overlapLength = lastLine.oldIndex - Math.max(removed.offset - diff.contextLength, 0);
+          removeContext = Math.min(overlapLength, diff.contextLength);
+          lastInfoChunk.lines = lastInfoChunk.lines.slice(0, lastInfoChunk.lines.length - removeContext);
+          lastLineNewIndex = lastInfoChunk.lines[lastInfoChunk.lines.length - 1].newIndex;
+        }
+      }
+
+      infoChunk = infoChunk || { offset: added.offset + 1, lines:[] };
+
+      var preContextRange = [Math.max(removed.offset - diff.contextLength, 0), Math.max(removed.offset, 0)]
+      var preContext = diff.lines1.slice(preContextRange[0], preContextRange[1])
+
+      helpers.each(preContext, function(line, i) {
+        var oldIx = preContextRange[0] + i + 1
+        var newIx = oldIx + totalAdded - totalRemoved
+        if (newIx > lastLineNewIndex) {
+          infoChunk.lines.push({oldIndex: oldIx, newIndex:newIx, line: line, type:"context"})
+        }
+      })
+
+      if (removed.length > 0) {
+        helpers.each(removed.chunk, function(line, i) {
+          var oldIx = removed.offset + i + 1
+          infoChunk.lines.push({oldIndex: oldIx, newIndex:null, line: line, type:"removed"})
+        })
+      }
+
+      if (added.length > 0) {
+        helpers.each(added.chunk, function(line, i) {
+          var newIx = added.offset + i + 1
+          infoChunk.lines.push({oldIndex: null, newIndex:newIx, line: line, type:"added"})
+        })
+      }
+
+      var postContextRange = [(added.offset - totalAdded + totalRemoved) + removed.length, (added.offset - totalAdded + totalRemoved) + diff.contextLength + removed.length]
+      var postContext = diff.lines1.slice(postContextRange[0], postContextRange[1])
+
+      helpers.each(postContext, function(line, i) {
+
+        var oldIx = postContextRange[0] + i + 1
+        var newIx = oldIx + added.length - removed.length + totalAdded - totalRemoved
+        infoChunk.lines.push({oldIndex: oldIx, newIndex:newIx, line: line, type:"context"})
+      });
+
+      totalAdded += added.length;
+      totalRemoved += removed.length;
+
+      if (infoChunk !== lastInfoChunk) {
+
+        infos.push(infoChunk);
+      }
+
+      lastInfoChunk = infoChunk;
+    })
+    return infos;
+  };
+
+  this.info = this.toInfo();
+
+  this.toString = function() {
+    return JSON.stringify(this.info);
+  };
+
+  this.stat = function() {
+
+    var result = {insertions: 0, deletions: 0}
+
+    helpers.each(this.info, function(chunk) {
+      helpers.each(chunk.lines, function(line) {
+        if (line.type == "context") {
+          // do nothing.
+        }
+        else if (line.type == "added") {
+          result.insertions += 1;
+        }
+        else if (line.type == "removed") {
+          result.deletions += 1;
+        }
+      });
+    });
+    return result;
+  };
+};