Fix CopilotCliRunner version parsing for 'GitHub Copilot CLI X.X.X' format (#14568)

* Fix CopilotCliRunner version parsing for 'GitHub Copilot CLI X.X.X' format

Extract version parsing into a testable TryParseVersionOutput method
that handles prefixed version strings like 'GitHub Copilot CLI 0.0.397'
by taking the last space-separated token before parsing.

Fixes #14174

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Address PR feedback: handle trailing punctuation in version string

Trim trailing period and other punctuation before parsing, to handle
output like 'GitHub Copilot CLI 0.0.397.' from the issue report.
Add test case for the trailing period format.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

---------

Co-authored-by: Mitch Denny <mitch@mitchdeny.com>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: 3 people

src/Aspire.Cli/Agents/CopilotCli/CopilotCliRunner.cs

@@ -52,28 +52,8 @@ internal sealed class CopilotCliRunner(ILogger<CopilotCliRunner> logger) : ICopi
             }
 
             var output = await outputTask.ConfigureAwait(false);
-            var versionString = output.Trim();
 
-            if (string.IsNullOrEmpty(versionString))
-            {
-                logger.LogDebug("GitHub Copilot CLI returned empty version output");
-                return null;
-            }
-
-            // Version output may be on the first line if multi-line
-            var lines = versionString.Split(['\n', '\r'], StringSplitOptions.RemoveEmptyEntries);
-            if (lines.Length > 0)
-            {
-                versionString = lines[0].Trim();
-            }
-
-            // Try to parse the version string (may have a 'v' prefix like "v1.2.3")
-            if (versionString.StartsWith('v') || versionString.StartsWith('V'))
-            {
-                versionString = versionString[1..];
-            }
-
-            if (SemVersion.TryParse(versionString, SemVersionStyles.Any, out var version))
+            if (TryParseVersionOutput(output, out var version))
             {
                 logger.LogDebug("Found GitHub Copilot CLI version: {Version}", version);
                 return version;
@@ -88,4 +68,40 @@ internal sealed class CopilotCliRunner(ILogger<CopilotCliRunner> logger) : ICopi
             return null;
         }
     }
+
+    internal static bool TryParseVersionOutput(string output, out SemVersion? version)
+    {
+        version = null;
+        var versionString = output.Trim();
+
+        if (string.IsNullOrEmpty(versionString))
+        {
+            return false;
+        }
+
+        // Version output may be on the first line if multi-line
+        var lines = versionString.Split(['\n', '\r'], StringSplitOptions.RemoveEmptyEntries);
+        if (lines.Length > 0)
+        {
+            versionString = lines[0].Trim();
+        }
+
+        // Try to extract the version from known formats like "GitHub Copilot CLI 0.0.397"
+        var lastSpaceIndex = versionString.LastIndexOf(' ');
+        if (lastSpaceIndex >= 0)
+        {
+            versionString = versionString[(lastSpaceIndex + 1)..];
+        }
+
+        // Trim common trailing punctuation that may follow the version (for example, "0.0.397.")
+        versionString = versionString.TrimEnd('.', ',', ')');
+
+        // Try to parse the version string (may have a 'v' prefix like "v1.2.3")
+        if (versionString.StartsWith('v') || versionString.StartsWith('V'))
+        {
+            versionString = versionString[1..];
+        }
+
+        return SemVersion.TryParse(versionString, SemVersionStyles.Any, out version);
+    }
 }

tests/Aspire.Cli.Tests/Agents/CopilotCliRunnerTests.cs

@@ -24,4 +24,37 @@ public async Task GetVersionAsync_ChecksForCopilot()
         // we just verify the method completes without throwing
         // Version can be null (not installed) or a real version
     }
+
+    [Theory]
+    [InlineData("GitHub Copilot CLI 0.0.397", 0, 0, 397)]
+    [InlineData("GitHub Copilot CLI 1.2.3", 1, 2, 3)]
+    [InlineData("0.0.397", 0, 0, 397)]
+    [InlineData("1.2.3", 1, 2, 3)]
+    [InlineData("v1.2.3", 1, 2, 3)]
+    [InlineData("V1.2.3", 1, 2, 3)]
+    [InlineData("GitHub Copilot CLI 0.0.397\nsome other output", 0, 0, 397)]
+    [InlineData("  GitHub Copilot CLI 0.0.397  ", 0, 0, 397)]
+    [InlineData("GitHub Copilot CLI 0.0.397.", 0, 0, 397)]
+    public void TryParseVersionOutput_ValidVersionStrings_ReturnsTrue(string input, int major, int minor, int patch)
+    {
+        var result = CopilotCliRunner.TryParseVersionOutput(input, out var version);
+
+        Assert.True(result);
+        Assert.NotNull(version);
+        Assert.Equal(major, version.Major);
+        Assert.Equal(minor, version.Minor);
+        Assert.Equal(patch, version.Patch);
+    }
+
+    [Theory]
+    [InlineData("")]
+    [InlineData("   ")]
+    [InlineData("not a version")]
+    public void TryParseVersionOutput_InvalidVersionStrings_ReturnsFalse(string input)
+    {
+        var result = CopilotCliRunner.TryParseVersionOutput(input, out var version);
+
+        Assert.False(result);
+        Assert.Null(version);
+    }
 }