chore: bump Go to 1.26.3 and centralize CLI build in integration tests

- Bump go to 1.26.3 and update GoBaseImage accordingly
- Use go 1.25.0 for integration go test as lowest version for compatibility
- Move CLI build out of individual tests into shared buildOpenFeatureCLI
- Fix golangci-lint issues
- Fix test/README.md and update new-generator.md

Signed-off-by: Roman Dmytrenko <rdmytrenko@gmail.com>

Author: erka

go.mod

@@ -1,6 +1,6 @@
 module github.com/open-feature/cli
 
-go 1.25.0
+go 1.26.3
 
 require (
 	dagger.io/dagger v0.20.6

internal/generators/csharp/csharp.go

@@ -69,7 +69,7 @@ func toCSharpDict(value any) string {
 	for _, key := range keys {
 		val := assertedMap[key]
 
-		builder.WriteString(fmt.Sprintf(".Set(%q, %s)", key, formatNestedValue(val)))
+		fmt.Fprintf(&builder, ".Set(%q, %s)", key, formatNestedValue(val))
 	}
 	builder.WriteString(".Build())")
 

internal/generators/golang/golang.go

@@ -90,7 +90,7 @@ func toMapLiteral(value any) string {
 		}
 		val := assertedMap[key]
 
-		builder.WriteString(fmt.Sprintf(`%q: %s`, key, formatNestedValue(val)))
+		fmt.Fprintf(&builder, `%q: %s`, key, formatNestedValue(val))
 	}
 
 	builder.WriteString("}")

internal/generators/java/java.go

@@ -73,7 +73,7 @@ func toMapLiteral(value any) string {
 		}
 		val := assertedMap[key]
 
-		builder.WriteString(fmt.Sprintf("%q, %s", key, formatNestedValue(val)))
+		fmt.Fprintf(&builder, "%q, %s", key, formatNestedValue(val))
 	}
 	builder.WriteString(")")
 

internal/generators/python/python.go

@@ -98,7 +98,7 @@ func toPythonDict(value any) string {
 		}
 		val := assertedMap[key]
 
-		builder.WriteString(fmt.Sprintf(`%q: %s`, key, formatNestedValue(val)))
+		fmt.Fprintf(&builder, `%q: %s`, key, formatNestedValue(val))
 	}
 
 	builder.WriteString("}")

internal/manifest/compare.go

@@ -68,8 +68,7 @@ func getKnownFlagProperties() map[string]bool {
 
 	// Extract fields from BaseFlag struct
 	t := reflect.TypeFor[BaseFlag]()
-	for i := range t.NumField() {
-		field := t.Field(i)
+	for field := range t.Fields() {
 		jsonTag := field.Tag.Get("json")
 		if jsonTag != "" {
 			// Extract field name from json tag (e.g., "flagType,omitempty" -> "flagType")

internal/manifest/validate.go

@@ -199,12 +199,10 @@ func FormatValidationError(issues []ValidationError) string {
 		if flagType == "" {
 			flagType = "missing"
 		}
-		sb.WriteString(fmt.Sprintf(
-			"- flagType: %s\n  flagPath: %s\n  errors:\n    ~ %s\n  \tSuggestions:\n      \t- flagType: boolean\n      \t- defaultValue: true\n\n",
+		fmt.Fprintf(&sb, "- flagType: %s\n  flagPath: %s\n  errors:\n    ~ %s\n  \tSuggestions:\n      \t- flagType: boolean\n      \t- defaultValue: true\n\n",
 			flagType,
 			path,
-			strings.Join(entry.messages, "\n    ~ "),
-		))
+			strings.Join(entry.messages, "\n    ~ "))
 	}
 	return sb.String()
 }

test/README.md

@@ -25,7 +25,7 @@ make test-integration
 
 ```bash
 # For C# tests
-make test-csharp-dagger
+make test-integration-csharp
 ```
 
 ## Adding a New Integration Test

test/integration/cmd/angular/run.go

@@ -11,21 +11,18 @@ import (
 )
 
 type Test struct {
-	ProjectDir string
+	projectDir string
 	TestDir    string
 }
 
 func New(projectDir, testDir string) *Test {
 	return &Test{
-		ProjectDir: projectDir,
+		projectDir: projectDir,
 		TestDir:    testDir,
 	}
 }
 
-func (t *Test) Run(ctx context.Context, client *dagger.Client) (*dagger.Container, error) {
-	// Mount the project source
-	source := client.Host().Directory(t.ProjectDir)
-
+func (t *Test) Run(ctx context.Context, client *dagger.Client, cli *dagger.Container) (*dagger.Container, error) {
 	// Mount the test files
 	testFiles := client.Host().Directory(t.TestDir, dagger.HostDirectoryOpts{
 		Include: []string{
@@ -37,14 +34,7 @@ func (t *Test) Run(ctx context.Context, client *dagger.Client) (*dagger.Containe
 		},
 	})
 
-	// Build the CLI in a Go container
-	cli := client.Container().
-		From(integration.GoBaseImage).
-		WithDirectory("/src", source).
-		WithWorkdir("/src").
-		WithExec([]string{"go", "build", "-o", "cli", "./cmd/openfeature"})
-
-	// Generate the Angular code
+	// Generate the Angular code using the pre-built CLI
 	generated := cli.WithExec([]string{
 		"./cli", "generate", "angular",
 		"--manifest=/src/sample/sample_manifest.json",
@@ -76,6 +66,10 @@ func (t *Test) Name() string {
 	return "angular"
 }
 
+func (t *Test) ProjectDir() string {
+	return t.projectDir
+}
+
 func main() {
 	ctx := context.Background()
 

test/integration/cmd/csharp/run.go

@@ -12,36 +12,28 @@ import (
 
 // Test implements the integration test for the C# generator
 type Test struct {
-	// ProjectDir is the absolute path to the root of the project
-	ProjectDir string
+	// projectDir is the absolute path to the root of the project
+	projectDir string
 	// TestDir is the absolute path to the test directory
 	TestDir string
 }
 
 // New creates a new Test
 func New(projectDir, testDir string) *Test {
 	return &Test{
-		ProjectDir: projectDir,
+		projectDir: projectDir,
 		TestDir:    testDir,
 	}
 }
 
 // Run executes the C# integration test using Dagger
-func (t *Test) Run(ctx context.Context, client *dagger.Client) (*dagger.Container, error) {
-	// Source code container
-	source := client.Host().Directory(t.ProjectDir)
+func (t *Test) Run(ctx context.Context, client *dagger.Client, cli *dagger.Container) (*dagger.Container, error) {
+	// Test source files
 	testFiles := client.Host().Directory(t.TestDir, dagger.HostDirectoryOpts{
 		Include: []string{"CompileTest.csproj", "Program.cs"},
 	})
 
-	// Build the CLI
-	cli := client.Container().
-		From(integration.GoBaseImage).
-		WithDirectory("/src", source).
-		WithWorkdir("/src").
-		WithExec([]string{"go", "build", "-o", "cli", "./cmd/openfeature"})
-
-	// Generate C# client
+	// Generate C# client using the pre-built CLI
 	generated := cli.WithExec([]string{
 		"./cli", "generate", "csharp",
 		"--manifest=/src/sample/sample_manifest.json",
@@ -70,6 +62,11 @@ func (t *Test) Name() string {
 	return "csharp"
 }
 
+// ProjectDir returns the absolute path to the project root
+func (t *Test) ProjectDir() string {
+	return t.projectDir
+}
+
 func main() {
 	ctx := context.Background()