deviation 0.1.0

deviation: ^0.1.0 copied to clipboard

A package for determining the differences between two lists and generating unified diff output similar to the diffutils CLI tool.

Installation #

To use package:deviation to generate diffs, first add it as a dependency in your pubspec.yaml file:

dart pub add deviation

Usage #

To compute the difference between two lists, create an instance of one of the supplied diff algorithms and pass the two lists to the algorithm's compute method.

import 'package:deviation/deviation.dart';

void main() {
  final diffPatch = const DiffAlgorithm.myers().compute(
    ['1', '2', '3'],
    ['2', '3', '4'],
  );
}

The compute method will return a Patch with a list of Update objects. If the Patch above is converted to a string representation and printed, you'd get an output similar to (-1, 2, 3, +4).

// Prints (-1,  2,  3, +4).
print(diffPatch.updates.map((u) => u.toString()));

For a more sophisticated textual output, you can convert a Patch into a UnifiedDiff that closely resembles the diffutils unified output format. For example, using the above patch with minimal configuration:

print(UnifiedDiff.fromPatch(
  diffPatch,
  header: const UnifiedDiffHeader.none(),
));

Would result in output similar to the following:

@@ -1,3 +1,3 @@
-1
 2
 3
+4