GitHub Actions Runner

src/Test/L0/Util/WhichUtilL0.cs

@@ -0,0 +1,74 @@
+using GitHub.Runner.Common.Util;
+using GitHub.Runner.Sdk;
+using System;
+using System.IO;
+using Xunit;
+
+namespace GitHub.Runner.Common.Tests.Util
+{
+    public sealed class WhichUtilL0
+    {
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Common")]
+        public void UseWhichFindGit()
+        {
+            using (TestHostContext hc = new TestHostContext(this))
+            {
+                //Arrange
+                Tracing trace = hc.GetTrace();
+
+                // Act.
+                string gitPath = WhichUtil.Which("git", trace: trace);
+
+                trace.Info($"Which(\"git\") returns: {gitPath ?? string.Empty}");
+
+                // Assert.
+                Assert.True(!string.IsNullOrEmpty(gitPath) && File.Exists(gitPath), $"Unable to find Git through: {nameof(WhichUtil.Which)}");
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Common")]
+        public void WhichReturnsNullWhenNotFound()
+        {
+            using (TestHostContext hc = new TestHostContext(this))
+            {
+                //Arrange
+                Tracing trace = hc.GetTrace();
+
+                // Act.
+                string nosuch = WhichUtil.Which("no-such-file-cf7e351f", trace: trace);
+
+                trace.Info($"result: {nosuch ?? string.Empty}");
+
+                // Assert.
+                Assert.True(string.IsNullOrEmpty(nosuch), "Path should not be resolved");
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Common")]
+        public void WhichThrowsWhenRequireAndNotFound()
+        {
+            using (TestHostContext hc = new TestHostContext(this))
+            {
+                //Arrange
+                Tracing trace = hc.GetTrace();
+
+                // Act.
+                try
+                {
+                    WhichUtil.Which("no-such-file-cf7e351f", require: true, trace: trace);
+                    throw new Exception("which should have thrown");
+                }
+                catch (FileNotFoundException ex)
+                {
+                    Assert.Equal("no-such-file-cf7e351f", ex.FileName);
+                }
+            }
+        }
+    }
+}