fix: changelog path option overwrites CHANGELOG.md if multiple projec…

…ts point to the same location (#148)

Detect duplicate changelog paths during config read.
Inform the user and exit with an error message.

Introduce new config folder tests with
ConfigProviderTests.cs

Versionize.Tests/Config/ConfigProviderTests.cs

@@ -0,0 +1,68 @@
+using McMaster.Extensions.CommandLineUtils;
+using Newtonsoft.Json;
+using Shouldly;
+using Versionize.CommandLine;
+using Versionize.Config;
+using Versionize.Tests.TestSupport;
+using Xunit;
+
+namespace Versionize.Tests.Config;
+
+public class ConfigProviderTests : IDisposable
+{
+    private readonly TestSetup _testSetup;
+    private readonly TestPlatformAbstractions _testPlatformAbstractions;
+
+    public ConfigProviderTests()
+    {
+        _testSetup = TestSetup.Create();
+
+        _testPlatformAbstractions = new TestPlatformAbstractions();
+        CommandLineUI.Platform = _testPlatformAbstractions;
+    }
+
+    [Fact]
+    public void ShouldExitIfChangelogPathsPointingToSameLocation()
+    {
+        var projects = new[]
+        {
+            new ProjectOptions
+            {
+                Name = "Project1",
+                Path = "project1",
+                Changelog = ChangelogOptions.Default with
+                {
+                    Header = "Project1 header",
+                    Path = "../docs"
+                }
+            },
+            new ProjectOptions
+            {
+                Name = "Project2",
+                Path = "project2",
+                Changelog = ChangelogOptions.Default with
+                {
+                    Header = "Project2 header",
+                    Path = "../docs"
+                }
+            }
+        };
+
+        var config = new FileConfig
+        {
+            SkipDirty = true,
+            Projects = projects
+        };
+        var json = JsonConvert.SerializeObject(config);
+        File.WriteAllText(Path.Join(_testSetup.WorkingDirectory, ".versionize"), json);
+        var cliConfig = CliConfig.Create(new CommandLineApplication());
+
+        Should.Throw<CommandLineExitException>(() => ConfigProvider.GetSelectedOptions(_testSetup.WorkingDirectory, cliConfig));
+        _testPlatformAbstractions.Messages[0].ShouldBe("Two or more projects have changelog paths pointing to the same location.");
+    }
+
+    public void Dispose()
+    {
+        _testSetup.Dispose();
+    }
+}

Versionize/Config/ConfigProvider.cs

@@ -16,6 +16,8 @@ public static VersionizeOptions GetSelectedOptions(string cwd, CliConfig cliConf
             fileConfig,
             cliConfig);
 
+        ValidateChangelogPaths(fileConfig, options.WorkingDirectory);
+
         CommandLineUI.Verbosity = MergeBool(cliConfig.Silent.HasValue(), fileConfig?.Silent)
             ? LogLevel.Silent
             : LogLevel.All;
@@ -92,4 +94,25 @@ private static bool MergeBool(bool overridingValue, bool? optionalValue)
     {
         return overridingValue ? overridingValue : (optionalValue ?? false);
     }
+
+    private static void ValidateChangelogPaths(FileConfig fileConfig, string cwd)
+    {
+        if (fileConfig?.Projects is null)
+        {
+            return;
+        }
+
+        var changelogPaths = new HashSet<string>();
+
+        foreach (var project in fileConfig.Projects)
+        {
+            var changelogPath = Path.Combine(cwd, project.Path, project.Changelog?.Path ?? string.Empty);
+            var fullChangelogPath = Path.GetFullPath(changelogPath);
+
+            if (!changelogPaths.Add(fullChangelogPath))
+            {
+                CommandLineUI.Exit("Two or more projects have changelog paths pointing to the same location.", 1);
+            }
+        }
+    }
 }