addr: remove support for defaulting plugin namespace and host

hcl2template/addrs/plugin.go

@@ -10,17 +10,13 @@ import (
 
 // Plugin encapsulates a single plugin type.
 type Plugin struct {
-	Type      string
-	Namespace string
 	Hostname  string
+	Namespace string
+	Type      string
 }
 
 func (p Plugin) RealRelativePath() string {
-	ns := DefaultPluginNamespace
+	return p.Namespace + "/packer-plugin-" + p.Type
-	if p.Namespace != "" {
-		ns = p.Namespace
-	}
-	return ns + "/packer-plugin-" + p.Type
 }
 
 func (p Plugin) Parts() []string {
@@ -34,20 +30,23 @@ func (p Plugin) String() string {
 // ForDisplay returns a user-friendly FQN string, simplified for readability. If
 // the plugin is using the default hostname, the hostname is omitted.
 func (p *Plugin) ForDisplay() string {
+	const (
+		// These will be hidden if they are a prefix
+		DefaultHashicorpPluginHost      = "github.com"
+		DefaultHashicorpPluginNamespace = "hashicorp"
+	)
+
 	parts := []string{}
-	if p.Hostname != DefaultPluginHost {
+	if p.Hostname != DefaultHashicorpPluginHost {
 		parts = append(parts, p.Hostname)
 	}
-	if p.Namespace != DefaultPluginNamespace {
+	if p.Namespace != DefaultHashicorpPluginNamespace {
 		parts = append(parts, p.Namespace)
 	}
 	parts = append(parts, p.Type)
 	return strings.Join(parts, "/")
 }
 
-const DefaultPluginHost = "github.com"
-const DefaultPluginNamespace = "hashicorp"
-
 // ParsePluginPart processes an addrs.Plugin namespace or type string
 // provided by an end-user, producing a normalized version if possible or
 // an error if the string contains invalid characters.
@@ -120,18 +119,18 @@ func IsPluginPartNormalized(str string) (bool, error) {
 // 		hostname/namespace/name
 func ParsePluginSourceString(str string) (*Plugin, hcl.Diagnostics) {
 	ret := &Plugin{
-		Hostname:  DefaultPluginHost,
+		Hostname:  "",
-		Namespace: DefaultPluginNamespace,
+		Namespace: "",
 	}
 	var diags hcl.Diagnostics
 
 	// split the source string into individual components
 	parts := strings.Split(str, "/")
-	if len(parts) == 0 || len(parts) > 3 {
+	if len(parts) != 3 {
 		diags = diags.Append(&hcl.Diagnostic{
 			Severity: hcl.DiagError,
 			Summary:  "Invalid plugin source string",
-			Detail:   `The "source" attribute must be in the format "[hostname/][namespace/]name"`,
+			Detail:   `The "source" attribute must be in the format "hostname/namespace/name"`,
 		})
 		return nil, diags
 	}
@@ -142,7 +141,7 @@ func ParsePluginSourceString(str string) (*Plugin, hcl.Diagnostics) {
 			diags = diags.Append(&hcl.Diagnostic{
 				Severity: hcl.DiagError,
 				Summary:  "Invalid plugin source string",
-				Detail:   `The "source" attribute must be in the format "[hostname/][namespace/]name"`,
+				Detail:   `The "source" attribute must be in the format "hostname/namespace/name"`,
 			})
 			return nil, diags
 		}
@@ -161,11 +160,6 @@ func ParsePluginSourceString(str string) (*Plugin, hcl.Diagnostics) {
 	}
 	ret.Type = name
 
-	if len(parts) == 1 {
-		return ret, diags
-	}
-
-	if len(parts) >= 2 {
 	// the namespace is always the second-to-last part
 	givenNamespace := parts[len(parts)-2]
 	namespace, err := ParsePluginPart(givenNamespace)
@@ -178,16 +172,9 @@ func ParsePluginSourceString(str string) (*Plugin, hcl.Diagnostics) {
 		return nil, diags
 	}
 	ret.Namespace = namespace
-	}
 
-	// Final Case: 3 parts
-	if len(parts) == 3 {
 	// the hostname is always the first part in a three-part source string
-		hostname := parts[0]
+	ret.Hostname = parts[0]
-		// TODO(azr): validate host ? Can this be something else than a
-		// github.com host for now?
-		ret.Hostname = hostname
-	}
 
 	// Due to how plugin executables are named and plugin git repositories
 	// are conventionally named, it's a reasonable and

hcl2template/addrs/plugin_test.go

@@ -0,0 +1,32 @@
+package addrs
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestParsePluginSourceString(t *testing.T) {
+	type args struct {
+		str string
+	}
+	tests := []struct {
+		args      args
+		want      *Plugin
+		wantDiags bool
+	}{
+		{args{"potato"}, nil, true},
+		{args{"hashicorp/azr"}, nil, true},
+		{args{"github.com/hashicorp/azr"}, &Plugin{"github.com", "hashicorp", "azr"}, false},
+	}
+	for _, tt := range tests {
+		t.Run(tt.args.str, func(t *testing.T) {
+			got, gotDiags := ParsePluginSourceString(tt.args.str)
+			if !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("ParsePluginSourceString() got = %v, want %v", got, tt.want)
+			}
+			if tt.wantDiags == (len(gotDiags) == 0) {
+				t.Errorf("Unexpected diags %s", gotDiags)
+			}
+		})
+	}
+}