Restore orignal output on generation fail

If the output file already exists, and the parser generator fails, the result is a empty file. This commit tries  to avoid this pitfall.
master
Futago-za Ryuu 6 years ago
parent 21a6de06d5
commit 2f0680ca16

@ -24,6 +24,12 @@ function readStream( inputStream, callback ) {
}
function closeStream( stream ) {
if ( stream !== process.stdin || stream !== process.stdout ) stream.end();
}
function abort( message ) {
console.error( message );
@ -33,36 +39,45 @@ function abort( message ) {
// Main
let inputStream, outputStream;
let inputStream, outputStream, orignalContent;
const inputFile = options.inputFile;
const outputFile = options.outputFile;
options.parser = options.parser || {};
if ( options.inputFile === "-" ) {
if ( inputFile === "-" ) {
process.stdin.resume();
inputStream = process.stdin;
inputStream.on( "error", () => {
abort( `Can't read from file "${ options.inputFile }".` );
abort( `Can't read from file "${ inputFile }".` );
} );
} else {
inputStream = fs.createReadStream( options.inputFile );
options.parser.filename = options.inputFile;
inputStream = fs.createReadStream( inputFile );
options.parser.filename = inputFile;
}
if ( options.outputFile === "-" ) {
if ( outputFile === "-" ) {
outputStream = process.stdout;
} else {
outputStream = fs.createWriteStream( options.outputFile );
if ( fs.existsSync( outputFile ) ) {
orignalContent = fs.readFileSync( outputFile, "utf8" );
}
outputStream = fs.createWriteStream( outputFile );
outputStream.on( "error", () => {
abort( `Can't write to file "${ options.outputFile }".` );
abort( `Can't write to file "${ outputFile }".` );
} );
@ -89,15 +104,18 @@ readStream( inputStream, input => {
}
return abort( e.message );
if ( orignalContent ) {
}
closeStream( outputStream );
fs.writeFileSync( outputFile, orignalContent, "utf8" );
outputStream.write( source );
if ( outputStream !== process.stdout ) {
}
outputStream.end();
return abort( e.message );
}
outputStream.write( source );
closeStream( outputStream );
} );

Loading…
Cancel
Save