fix(cli): resolve CLI-002..007 — robust response rendering, URL/JSON arg validation, credential env-vars, doc refresh

tests/ScadaLink.CLI.Tests/CredentialResolutionTests.cs

@@ -0,0 +1,71 @@
+using ScadaLink.CLI;
+
+namespace ScadaLink.CLI.Tests;
+
+/// <summary>
+/// Regression tests for CLI-006 — credentials could only be supplied via the
+/// <c>--password</c> command-line option, which leaks into process listings and
+/// shell history. A <c>SCADALINK_PASSWORD</c> / <c>SCADALINK_USERNAME</c> environment
+/// fallback gives CI/CD a safer alternative.
+/// </summary>
+[Collection("Environment")]
+public class CredentialResolutionTests
+{
+    [Fact]
+    public void Load_Password_FromEnvironment()
+    {
+        var orig = Environment.GetEnvironmentVariable("SCADALINK_PASSWORD");
+        try
+        {
+            Environment.SetEnvironmentVariable("SCADALINK_PASSWORD", "s3cret");
+
+            var config = CliConfig.Load();
+
+            Assert.Equal("s3cret", config.Password);
+        }
+        finally
+        {
+            Environment.SetEnvironmentVariable("SCADALINK_PASSWORD", orig);
+        }
+    }
+
+    [Fact]
+    public void Load_Username_FromEnvironment()
+    {
+        var orig = Environment.GetEnvironmentVariable("SCADALINK_USERNAME");
+        try
+        {
+            Environment.SetEnvironmentVariable("SCADALINK_USERNAME", "ci-user");
+
+            var config = CliConfig.Load();
+
+            Assert.Equal("ci-user", config.Username);
+        }
+        finally
+        {
+            Environment.SetEnvironmentVariable("SCADALINK_USERNAME", orig);
+        }
+    }
+
+    [Fact]
+    public void Load_NoCredentialEnvVars_LeavesCredentialsNull()
+    {
+        var origUser = Environment.GetEnvironmentVariable("SCADALINK_USERNAME");
+        var origPass = Environment.GetEnvironmentVariable("SCADALINK_PASSWORD");
+        try
+        {
+            Environment.SetEnvironmentVariable("SCADALINK_USERNAME", null);
+            Environment.SetEnvironmentVariable("SCADALINK_PASSWORD", null);
+
+            var config = CliConfig.Load();
+
+            Assert.Null(config.Username);
+            Assert.Null(config.Password);
+        }
+        finally
+        {
+            Environment.SetEnvironmentVariable("SCADALINK_USERNAME", origUser);
+            Environment.SetEnvironmentVariable("SCADALINK_PASSWORD", origPass);
+        }
+    }
+}