Preserve line endings and trailing newline when updating image tags (SF-3581)

source/Calamari.Common/Plumbing/Extensions/StringExtensions.cs

@@ -99,6 +99,11 @@ public static string ToCamelCase(this string text)
                         : null;
         }
 
+        public static bool HasTrailingNewLine(this string? input)
+        {
+            return input != null && (input.EndsWith("\n") || input.EndsWith("\r"));
+        }
+
         public static string EnsureDoubleQuoteIfContainsSpaces(this string text) => EnsureDoubleQuote(text, t => t.Contains(" "));
         public static string EnsureDoubleQuote(this string text) => EnsureDoubleQuote(text, t => !t.EndsWith("\"") && !t.StartsWith("\""));
         public static string EnsureDoubleQuote(this string text, Predicate<string> shouldQuote) => shouldQuote(text) ? $"\"{text}\"" : text;

source/Calamari.Tests/ArgoCD/Helm/HelmValuesEditorTests.cs

@@ -98,29 +98,34 @@ public void GenerateVariableDictionary_ReturnsDictionaryOfNodeValuesWithValues()
             result.Should().BeEquivalentTo(expected);
         }
 
-        [Test]
-        public void UpdateNodeValue_ReturnsModifiedYaml()
+        [TestCase("\n")]
+        [TestCase("\r\n")]
+        public void UpdateNodeValue_ReturnsModifiedYaml(string newLine)
         {
-            const string yamlContent = @"root:
-  node1: ""node1value""
-  node2:
-     node2Nest:
-         node2nestedValue: ""banana""
-     node2Child1: ""node2child1value""
-     node2Child2: 42
-";
+            var yamlContent = """
+                              root:
+                                node1: "node1value"
+                                node2:
+                                   node2Nest:
+                                       node2nestedValue: "banana"
+                                   node2Child1: "node2child1value"
+                                   node2Child2: 42
+
+                              """.ReplaceLineEndings(newLine);
+
             var result = HelmValuesEditor.UpdateNodeValue(yamlContent, "root.node1", "awesome new value");
 
-            const string expected = @"root:
-  node1: ""awesome new value""
-  node2:
-     node2Nest:
-         node2nestedValue: ""banana""
-     node2Child1: ""node2child1value""
-     node2Child2: 42
-";
-            //ensure platform-agnostic multiline comparison
-            result.ReplaceLineEndings().Should().Be(expected.ReplaceLineEndings());
+            var expected = """
+                           root:
+                             node1: "awesome new value"
+                             node2:
+                                node2Nest:
+                                    node2nestedValue: "banana"
+                                node2Child1: "node2child1value"
+                                node2Child2: 42
+
+                           """.ReplaceLineEndings(newLine);
+            result.Should().Be(expected);
         }
     }
 }

source/Calamari.Tests/ArgoCD/Helm/HelmValuesImageReplaceStepVariablesTests.cs

@@ -1,5 +1,4 @@
-using System;
-using System.Collections.Generic;
+using System.Collections.Generic;
 using Calamari.ArgoCD;
 using Calamari.ArgoCD.Conventions;
 using Calamari.ArgoCD.Models;
@@ -122,13 +121,15 @@ public void StructuredValue_ImageOnNonDefaultRegistry_UpdatesFullRefAndTracksWit
     [Test]
     public void TwoImagesWithSameTag_OnlyUpdatesConfiguredPath()
     {
-        const string yaml = @"
-nginx:
-  tag: 1.0
-redis:
-  tag: 1.0
-";
-
+        const string yaml = """
+
+                            nginx:
+                              tag: 1.0
+                            redis:
+                              tag: 1.0
+
+                            """;
+
         var replacer = new HelmValuesImageReplaceStepVariables(yaml, DefaultRegistry, log);
         var images = new List<ContainerImageReferenceAndHelmReference>
         {
@@ -137,10 +138,86 @@ public void TwoImagesWithSameTag_OnlyUpdatesConfiguredPath()
 
         var result = replacer.UpdateImages(images);
 
+        const string expectedYaml = """
+
+                                    nginx:
+                                      tag: 1.27.1
+                                    redis:
+                                      tag: 1.0
+
+                                    """;
+
         using var scope = new AssertionScope();
         result.UpdatedImageReferences.Should().BeEquivalentTo(["nginx:1.27.1"]);
-        result.UpdatedContents.Should().Contain($"nginx:{Environment.NewLine}  tag: 1.27.1");
-        result.UpdatedContents.Should().Contain($"redis:{Environment.NewLine}  tag: 1.0");
+        result.UpdatedContents.ReplaceLineEndings("\n").Should().Be(expectedYaml.ReplaceLineEndings("\n"));
+    }
+
+    // The endings are forced with ReplaceLineEndings rather than inherited from the literal:
+    // .gitattributes checks .cs files out with native endings, so an inherited ending always matches
+    // Environment.NewLine and the assertion cannot distinguish "preserved the input's endings" from
+    // "used the agent's". The customer's case was an LF file on a Windows agent.
+    [TestCase("\n")]
+    [TestCase("\r\n")]
+    public void UpdatedYaml_PreservesTheInputLineEndings(string newLine)
+    {
+        var yaml = """
+
+                   nginx:
+                     tag: 1.0
+                   redis:
+                     tag: 1.0
+
+                   """.ReplaceLineEndings(newLine);
+
+        var replacer = new HelmValuesImageReplaceStepVariables(yaml, DefaultRegistry, log);
+        var images = new List<ContainerImageReferenceAndHelmReference>
+        {
+            new(ContainerImageReference.FromReferenceString("nginx:1.27.1", DefaultRegistry), "nginx.tag")
+        };
+
+        var result = replacer.UpdateImages(images);
+
+        var expectedYaml = """
+
+                           nginx:
+                             tag: 1.27.1
+                           redis:
+                             tag: 1.0
+
+                           """.ReplaceLineEndings(newLine);
+
+        result.UpdatedContents.Should().Be(expectedYaml);
+    }
+
+    [TestCase("\n")]
+    [TestCase("\r\n")]
+    public void UpdatedYaml_WithoutATrailingNewline_DoesNotAddOne(string newLine)
+    {
+        var yaml = """
+
+                   nginx:
+                     tag: 1.0
+                   redis:
+                     tag: 1.0
+                   """.ReplaceLineEndings(newLine);
+
+        var replacer = new HelmValuesImageReplaceStepVariables(yaml, DefaultRegistry, log);
+        var images = new List<ContainerImageReferenceAndHelmReference>
+        {
+            new(ContainerImageReference.FromReferenceString("nginx:1.27.1", DefaultRegistry), "nginx.tag")
+        };
+
+        var result = replacer.UpdateImages(images);
+
+        var expectedYaml = """
+
+                           nginx:
+                             tag: 1.27.1
+                           redis:
+                             tag: 1.0
+                           """.ReplaceLineEndings(newLine);
+
+        result.UpdatedContents.Should().Be(expectedYaml);
     }
 
     [Test]