fix(planner/nodejs): Initialize map (#122)

internal/nodejs/package.go

@@ -14,21 +14,22 @@ type PackageJSONEngine struct {
 
 // PackageJSON is the structure of `package.json`.
 type PackageJSON struct {
-	PackageManager  *string           `json:"packageManager"`
-	Dependencies    map[string]string `json:"dependencies"`
-	DevDependencies map[string]string `json:"devDependencies"`
-	Scripts         map[string]string `json:"scripts"`
+	PackageManager  *string           `json:"packageManager,omitempty"`
+	Dependencies    map[string]string `json:"dependencies,omitempty"`
+	DevDependencies map[string]string `json:"devDependencies,omitempty"`
+	Scripts         map[string]string `json:"scripts,omitempty"`
 	Engines         PackageJSONEngine `json:"engines"`
 	Main            string            `json:"main"`
 }
 
 // NewPackageJSON returns a new instance of PackageJson
 // with some default values.
 func NewPackageJSON() PackageJSON {
-	// we don't need to allocate an map for Dependencies,
-	// DevDependencies and Scripts, since we won't set them
-	// in the null state.
-	return PackageJSON{}
+	return PackageJSON{
+		Dependencies:    make(map[string]string),
+		DevDependencies: make(map[string]string),
+		Scripts:         make(map[string]string),
+	}
 }
 
 // DeserializePackageJSON deserializes a package.json file

internal/nodejs/package_test.go

@@ -30,11 +30,6 @@ func TestNewPackageJson(t *testing.T) {
 		assert.False(t, ok)
 	})
 
-	// panic!
-	assert.Panics(t, func() {
-		p.Scripts["build"] = "hi"
-	})
-
 	// engines
 	assert.Empty(t, p.Engines.Node)
 
@@ -63,9 +58,9 @@ func TestDeserializePackageJson_EmptyJson(t *testing.T) {
 
 	p, err := nodejs.DeserializePackageJSON(fs)
 	assert.NoError(t, err)
-	assert.Nil(t, p.Dependencies)
-	assert.Nil(t, p.DevDependencies)
-	assert.Nil(t, p.Scripts)
+	assert.Empty(t, p.Dependencies)
+	assert.Empty(t, p.DevDependencies)
+	assert.Empty(t, p.Scripts)
 	assert.Empty(t, p.Engines.Node)
 	assert.Empty(t, p.Main)
 }