Adding more unit testing

Signed-off-by: Juan Bustamante <jbustamante@vmware.com>

pkg/cnb/env_vars.go

@@ -23,8 +23,18 @@ func serializeEnvVars(envVars []envVariable, platformDir string) error {
 	return nil
 }
 
+func mergeEnvVariables(old []envVariable, new []envVariable) []envVariable {
+	mergedEnv := new
+	for _, v := range old {
+		if !containsEnvVar(new, v) {
+			mergedEnv = append(mergedEnv, v)
+		}
+	}
+	return mergedEnv
+}
+
 func containsEnvVar(envVars []envVariable, v envVariable) bool {
-	var found bool = false
+	var found = false
 	for _, x := range envVars {
 		if x.Name == v.Name {
 			found = true

pkg/cnb/env_vars_test.go

@@ -0,0 +1,121 @@
+package cnb
+
+import (
+	"github.com/stretchr/testify/assert"
+	"testing"
+
+	"github.com/sclevine/spec"
+)
+
+func TestEnvVariable(t *testing.T) {
+	spec.Run(t, "EnvVariable", testEnvVariable)
+}
+
+func testEnvVariable(t *testing.T, when spec.G, it spec.S) {
+
+	var (
+		variableA, variableB            envVariable
+		envVariables, otherEnvVariables []envVariable
+	)
+
+	when("#containsEnvVar", func() {
+		when("slide is undefined", func() {
+			it.Before(func() {
+				envVariables = nil
+				variableA = envVariable{}
+			})
+
+			it("returns false", func() {
+				assert.False(t, containsEnvVar(envVariables, variableA))
+			})
+		})
+
+		when("slide is defined", func() {
+			it.Before(func() {
+				variableA = envVariable{Name: "NameA", Value: "ValueA"}
+				envVariables = []envVariable{variableA}
+			})
+
+			when("element is present in the slide", func() {
+				it("returns true", func() {
+					assert.True(t, containsEnvVar(envVariables, envVariable{Name: "NameA", Value: "Whatever"}))
+				})
+			})
+
+			when("element is not present in the slide", func() {
+				it("returns false", func() {
+					assert.False(t, containsEnvVar(envVariables, envVariable{Name: "NameB", Value: "Whatever"}))
+				})
+			})
+		})
+	})
+
+	when("#mergeEnvVariables", func() {
+		when("slides are undefined", func() {
+			when("both slides are undefined", func() {
+				it.Before(func() {
+					envVariables = nil
+					otherEnvVariables = nil
+				})
+
+				it("returns nil", func() {
+					merged := mergeEnvVariables(envVariables, otherEnvVariables)
+					assert.Nil(t, merged)
+				})
+			})
+
+			when("one of the slide is undefined", func() {
+				it.Before(func() {
+					envVariables = nil
+					variableA = envVariable{Name: "NameA", Value: "ValueA"}
+					otherEnvVariables = []envVariable{variableA}
+				})
+
+				when("old slide is undefined", func() {
+					it("returns new slide", func() {
+						merged := mergeEnvVariables(envVariables, otherEnvVariables)
+						assert.Equal(t, otherEnvVariables, merged)
+					})
+				})
+
+				when("new slide is undefined", func() {
+					it("returns old slide", func() {
+						merged := mergeEnvVariables(otherEnvVariables, envVariables)
+						assert.Equal(t, otherEnvVariables, merged)
+					})
+				})
+			})
+
+			when("slides are defined", func() {
+				when("element in old slide does not exist in new slide", func() {
+					it.Before(func() {
+						variableA = envVariable{Name: "NameA", Value: "ValueA"}
+						variableB = envVariable{Name: "NameB", Value: "ValueB"}
+						envVariables = []envVariable{variableA}
+						otherEnvVariables = []envVariable{variableB}
+					})
+
+					it("element is added to the merge slide", func() {
+						merged := mergeEnvVariables(envVariables, otherEnvVariables)
+						expected := []envVariable{variableB, variableA}
+						assert.Equal(t, expected, merged)
+					})
+				})
+
+				when("element in old slide is also defined in new slide", func() {
+					it.Before(func() {
+						variableA = envVariable{Name: "NameA", Value: "ValueA"}
+						variableB = envVariable{Name: "NameA", Value: "OtherValue"}
+						envVariables = []envVariable{variableA}
+						otherEnvVariables = []envVariable{variableB}
+					})
+
+					it("element in new slide has precedence", func() {
+						merged := mergeEnvVariables(envVariables, otherEnvVariables)
+						assert.Equal(t, otherEnvVariables, merged)
+					})
+				})
+			})
+		})
+	})
+}

pkg/cnb/project_descriptor.go

@@ -126,16 +126,6 @@ func getEnvVariables(d descriptorV2) []envVariable {
 	return env
 }
 
-func mergeEnvVariables(old []envVariable, new []envVariable) []envVariable {
-	mergedEnv := new
-	for _, v := range old {
-		if !containsEnvVar(new, v) {
-			mergedEnv = append(mergedEnv, v)
-		}
-	}
-	return mergedEnv
-}
-
 func getFileFilter(d build) (func(string) bool, error) {
 	if d.Exclude != nil && d.Include != nil {
 		return nil, fmt.Errorf("project descriptor cannot have both include and exclude defined")