265 lines
7.4 KiB
JavaScript
265 lines
7.4 KiB
JavaScript
'use strict';
|
|
|
|
var _ = require('lodash'),
|
|
temp = require('temp'),
|
|
fs = require('fs'),
|
|
exec = require('child_process').exec,
|
|
Lexer = require('lex');
|
|
|
|
// Automatically track and cleanup files at exit
|
|
temp.track();
|
|
|
|
// Perform a comparison between a and b
|
|
// the callback should have parameters (err, result)
|
|
module.exports = function(a, b, asMarkdown, callback) {
|
|
|
|
//!!! this nested file-open is not a good pattern
|
|
// better would be to use promises and write the two files asynchronously
|
|
|
|
// open the first file
|
|
temp.open('wdiffa-', function(err, filea) {
|
|
//handle errors
|
|
if (err)
|
|
return callback(err);
|
|
|
|
//write the string to the file
|
|
fs.write(filea.fd, a);
|
|
|
|
//close the file
|
|
fs.close(filea.fd, function(err) {
|
|
if (err)
|
|
return callback(err);
|
|
|
|
//open the second file
|
|
temp.open('wdiffa-', function(err, fileb) {
|
|
if (err)
|
|
return callback(err);
|
|
|
|
//write the string to the file
|
|
fs.write(fileb.fd, b);
|
|
|
|
//close the file
|
|
fs.close(fileb.fd, function(err) {
|
|
if (err)
|
|
return callback(err);
|
|
|
|
var cmd = "./bin/wdiff " + filea.path + " " +fileb.path;
|
|
exec(cmd, function(err, stdout) {
|
|
|
|
if (err && err.code!=1 && err.code!=0) {
|
|
return callback(err);
|
|
}
|
|
//if no difference was found by wdiff, err.code will be 0
|
|
var wdiffSame;
|
|
wdiffSame = (err && err.code == 0) ? true:false;
|
|
|
|
|
|
var resData = {wdiffNoMarkdown:stdout, same: wdiffSame};
|
|
if (asMarkdown) {
|
|
|
|
//!!! this needs more sophisticated parsing
|
|
|
|
var markdown = rewriteWdiffMarkdown(stdout)
|
|
|
|
resData.wdiff=markdown;
|
|
}
|
|
|
|
return callback(null, resData);
|
|
});
|
|
});
|
|
});
|
|
});
|
|
});
|
|
}
|
|
|
|
/* Rewrites the given wdiff output to correctly render as markdown,
|
|
assuming the source documents were also valid markdown. */
|
|
function rewriteWdiffMarkdown(source) {
|
|
//initialize a stack for the lexed input
|
|
//make it a lodash container, just for kicks
|
|
var tokens = _([]);
|
|
|
|
//define tokens
|
|
var LDEL = {type:"LDEL"}, RDEL = {type:"RDEL"}, LINS = {type:"LINS"}, RINS = {type:"RINS"};
|
|
//var STRING = {type: "STRING", value:""};
|
|
var RDEL_LINS = {type:"RDEL_LINS"};
|
|
var NEWLINE = {type:"\n"};
|
|
|
|
var isStringToken = function (token) { return token.type == "STRING";}
|
|
|
|
|
|
//create a lexer to process the wdiff string
|
|
var lexer = new Lexer(function (char) {
|
|
//the default rule creates a string on the stack for unmatched characters
|
|
//and just adds characters to it as they come in
|
|
if (tokens.size() == 0 || !isStringToken(tokens.last()))
|
|
tokens.push({type: "STRING", value:""});
|
|
|
|
tokens.last().value += char;
|
|
});
|
|
|
|
//rules for the newline character,
|
|
//as well as opening and closing (left and right) delete and insert tokens
|
|
lexer
|
|
.addRule(/\[-/, function () {
|
|
tokens.push(LDEL);
|
|
})
|
|
.addRule(/-\]/, function () {
|
|
tokens.push(RDEL);
|
|
})
|
|
.addRule(/{\+/, function () {
|
|
tokens.push(LINS);
|
|
})
|
|
.addRule(/\+}/, function () {
|
|
tokens.push(RINS);
|
|
})
|
|
//we have a special rule for joined delete and insert tokens
|
|
.addRule(/-\] {\+/, function() {
|
|
tokens.push(RDEL_LINS);
|
|
})
|
|
.addRule(/\n/, function () {
|
|
//tokens.push({type:"STRING", value:"\n"})
|
|
tokens.push(NEWLINE);
|
|
})
|
|
;
|
|
|
|
|
|
//do the lexing
|
|
lexer.setInput(source);
|
|
lexer.lex();
|
|
|
|
//# now we parse and transform the input
|
|
|
|
//create a stack for the transformed output
|
|
var transform = _([]);
|
|
|
|
//set the state variables for the parse
|
|
var SSTRING = "string", SINS = "ins", SDEL = "del", SDELINS = "delins";
|
|
var state = SSTRING;
|
|
|
|
//this is the index of the immediately previous delete string in the transform stack
|
|
var deleteStartIndex = -1
|
|
|
|
//iterate the input tokens to create the intermediate representation
|
|
tokens.forEach(function(token) {
|
|
//we add string tokens to the transformed stack
|
|
if (isStringToken(token)) {
|
|
//add the string with state information
|
|
var item = {
|
|
string: token.value,
|
|
state: state
|
|
};
|
|
//if this is the DELINS state, we will put the string in the transformed stack in a different order
|
|
// the INS string is spliced into place just after the first DEL string
|
|
// the point of this is so that the preceeding markdown formatting instructions
|
|
// on this line are applied equally to the del and ins strings
|
|
// an extra space is inserted between DEL and INS items, for readibility
|
|
if (state == SDELINS) {
|
|
state = SINS;
|
|
item.state = SINS;
|
|
var spaceItem = {string: ' ', state: SSTRING};
|
|
transform.splice(deleteStartIndex+1, 0, item);
|
|
transform.splice(deleteStartIndex+1, 0, spaceItem);
|
|
|
|
}
|
|
else {
|
|
transform.push(item);
|
|
}
|
|
}
|
|
//the various tokens control the transformation mode
|
|
if (token == LDEL) {
|
|
state = SDEL;
|
|
deleteStartIndex = transform.size();
|
|
}
|
|
if (token == LINS) {
|
|
state = SINS;
|
|
}
|
|
if (token == RDEL || token == RINS) {
|
|
state = SSTRING;
|
|
deleteStartIndex = -1;
|
|
}
|
|
if (token == RDEL_LINS) {
|
|
state = SDELINS;
|
|
}
|
|
|
|
if (token == NEWLINE) {
|
|
transform.push({string: '\n', state: state});
|
|
}
|
|
|
|
//ignore newlines (they get added to the output)
|
|
});
|
|
|
|
|
|
// * now emit the output string
|
|
var output = "";
|
|
var newline = true;
|
|
var newlineIndex = -1;
|
|
|
|
// prefixes are matched as follows:
|
|
// ^ - start of line
|
|
// ([ \t]*\>)* - blockquotes (possibly nested)
|
|
// (
|
|
// ([ \t]*#*) - headers
|
|
// |([ \t]+[\*\+-]) - unordered lists
|
|
// |([ \t]+[0-9]+\.) - numeric lists
|
|
// )?
|
|
// [ \t]+ - trailing whitespace
|
|
//var PREFIX = /^([ \t]*\>)*(([ \t]*#*)|([ \t]*[\*\+-])|([ \t]*[\d]+\.))?[ \t]+/
|
|
var PREFIX = /^([ \t]*\>)*(([ \t]*#*)|([ \t]*[\*\+-])|([ \t]*[\d]+\.))?[ \t]*/
|
|
//var PREFIX = /^#*/
|
|
|
|
|
|
transform.forEach(function(item) {
|
|
//newlines are undecorated
|
|
if (item.string == '\n') {
|
|
output += '\n';
|
|
|
|
//flag the new line
|
|
newline = true;
|
|
//and record the offset in the output string
|
|
newlineIndex = output.length;
|
|
return
|
|
}
|
|
|
|
//wrap del strings with tags
|
|
if (item.state == SDEL) {
|
|
output += '<del>' + item.string + '</del>';
|
|
//del doesn't reset the newline state
|
|
}
|
|
|
|
//ins strings have to be handled a little differently:
|
|
//if this is an ins just after a newline, or after a del after a newline, we need to peel off any markdown formatting prefixes and insert them at the beginning of the line outside the del/ins tags
|
|
else if (item.state == SINS && newline) {
|
|
var prestring, poststring;
|
|
var match = item.string.match(PREFIX);
|
|
if (match == null)
|
|
prestring ="";
|
|
else
|
|
prestring = match[0];
|
|
|
|
poststring = item.string.substring(prestring.length);
|
|
|
|
output = output.substring(0, newlineIndex) + prestring + output.substring(newlineIndex);
|
|
output += '<ins>' + poststring + '</ins>';
|
|
newline = false;
|
|
newlineIndex = -1;
|
|
|
|
}
|
|
|
|
else if (item.state == SINS) {
|
|
output += '<ins>' + item.string + '</ins>';
|
|
}
|
|
|
|
//and just output other strings
|
|
else {
|
|
output += item.string;
|
|
//this resets the newline state
|
|
newline = false;
|
|
newlineIndex = -1;
|
|
}
|
|
|
|
});
|
|
|
|
return output;
|
|
}
|