Add coverage for package secret

Author: saucow

CONTRIBUTING.md

@@ -33,6 +33,10 @@ make test
 
 # Run integration tests (requires Docker plugin to be installed)
 make integration
+
+# Run integration tests with console output
+docker buildx build --build-arg GO_LDFLAGS --build-arg DOCKER_MCP_PLUGIN_BINARY --target=test --progress=plain --no-cache .
+
 ```
 
 ### Unit Test Coverage

cmd/docker-mcp/secret-management/secret/secret_test.go

@@ -0,0 +1,62 @@
+package secret
+
+import (
+	"errors"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestGetSecretKey(t *testing.T) {
+	result := getSecretKey("mykey")
+	assert.Equal(t, "sm_mykey", result)
+}
+
+func TestParseArg(t *testing.T) {
+	// Test key=value parsing
+	secret, err := ParseArg("key=value", SetOpts{Provider: Credstore})
+	assert.NoError(t, err)
+	assert.Equal(t, "key", secret.key)
+	assert.Equal(t, "value", secret.val)
+
+	// Test key-only for non-direct providers
+	secret, err = ParseArg("keyname", SetOpts{Provider: "oauth/github"})
+	assert.NoError(t, err)
+	assert.Equal(t, "keyname", secret.key)
+	assert.Equal(t, "", secret.val)
+
+	// Test error on key=value with non-direct provider
+	_, err = ParseArg("key=value", SetOpts{Provider: "oauth/github"})
+	assert.Error(t, err)
+}
+
+func TestIsDirectValueProvider(t *testing.T) {
+	assert.True(t, isDirectValueProvider(""))
+	assert.True(t, isDirectValueProvider(Credstore))
+	assert.False(t, isDirectValueProvider("oauth/github"))
+}
+
+func TestIsValidProvider(t *testing.T) {
+	// Valid providers
+	assert.True(t, IsValidProvider(""))
+	assert.True(t, IsValidProvider(Credstore))
+	assert.True(t, IsValidProvider("oauth/github"))
+	assert.True(t, IsValidProvider("oauth/google"))
+
+	// Invalid providers
+	assert.False(t, IsValidProvider("invalid"))
+	assert.False(t, IsValidProvider("oauth"))
+}
+
+func TestIsErrDecryption(t *testing.T) {
+	// Test decryption error detection
+	decryptErr := errors.New("gpg: decryption failed: No secret key")
+	assert.True(t, isErrDecryption(decryptErr))
+
+	// Test other errors
+	otherErr := errors.New("some other error")
+	assert.False(t, isErrDecryption(otherErr))
+
+	// Test nil
+	assert.False(t, isErrDecryption(nil))
+}