GrahamTheCoder

function Get-LinesChanged() {
	$diffFromCommonBase = git diff origin/master...HEAD --unified=0 --dst-prefix=""
		
	$linesByFile = @{}
	$currentLines = New-Object System.Collections.ArrayList
	foreach ($diffLine in $diffFromCommonBase ) {
		if ($diffLine.StartsWith("+++")) {
			#e.g. "+++ Path/to/file.cs" -> "Path/to/file.cs"
			$currentFile = $diffLine.Substring(4)
			$currentLines = $linesByFile[$currentFile] = New-Object System.Collections.ArrayList

GrahamTheCoder

    public static class DictionaryExtensions
    {
        public static TValue Get<TKey, TValue>(this IReadOnlyDictionary<TKey, TValue> dict, TKey key, TValue defaultValue = default(TValue))
            => dict.TryGetValue(key, out var actualValue) ? actualValue : defaultValue;

        public static TValue Get<TKey, TValue>(this IDictionary<TKey, TValue> dict, TKey key, TValue defaultValue = default(TValue))
            => dict.TryGetValue(key, out var actualValue) ? actualValue : defaultValue;

        public static TValue Get<TKey, TValue>(this Dictionary<TKey, TValue> dict, TKey key, TValue defaultValue = default(TValue))