fix: allow unexported :extend for inferred packages

Author: jmattheis

config/converter.go

@@ -9,7 +9,6 @@ import (
 	"github.com/jmattheis/goverter/config/parse"
 	"github.com/jmattheis/goverter/enum"
 	"github.com/jmattheis/goverter/method"
-	"github.com/jmattheis/goverter/pkgload"
 )
 
 const (
@@ -46,8 +45,23 @@ type Converter struct {
 	FileName string
 	typ      types.Type
 	Methods  []*Method
-
 	Location string
+
+	packageConfigured bool
+}
+
+func (c *Converter) inferOutputPackage(ctx *context) {
+	if !c.packageConfigured || c.OutputPackagePath == "" {
+		if targetPackage, err := resolvePackage(c.FileName, c.Package, c.OutputFile); err == nil {
+			c.OutputPackagePath = targetPackage
+		}
+	}
+
+	if !c.packageConfigured || c.OutputPackageName == "" {
+		if pkg := ctx.Loader.GetUncheckedPkg(c.OutputPackagePath); pkg != nil {
+			c.OutputPackageName = pkg.Types.Name()
+		}
+	}
 }
 
 func (c *Converter) typeForMethod() types.Type {
@@ -97,7 +111,7 @@ func defaultOutputFile(name string) string {
 }
 
 func parseConverter(ctx *context, rawConverter *RawConverter, global RawLines) (*Converter, error) {
-	c, err := initConverter(ctx.Loader, rawConverter)
+	c, err := initConverter(ctx, rawConverter)
 	if err != nil {
 		return nil, err
 	}
@@ -109,34 +123,11 @@ func parseConverter(ctx *context, rawConverter *RawConverter, global RawLines) (
 		return nil, err
 	}
 
-	resolveOutputPackage(ctx, c)
-
 	err = parseMethods(ctx, rawConverter, c)
 	return c, err
 }
 
-func resolveOutputPackage(ctx *context, c *Converter) {
-	targetPackage, err := resolvePackage(c.FileName, c.Package, c.OutputFile)
-	if err != nil {
-		return
-	}
-
-	if c.OutputPackagePath == "" {
-		c.OutputPackagePath = targetPackage
-	}
-
-	pkg := ctx.Loader.GetUncheckedPkg(targetPackage)
-
-	if pkg == nil {
-		return
-	}
-
-	if c.OutputPackageName == "" {
-		c.OutputPackageName = pkg.Types.Name()
-	}
-}
-
-func initConverter(loader *pkgload.PackageLoader, rawConverter *RawConverter) (*Converter, error) {
+func initConverter(ctx *context, rawConverter *RawConverter) (*Converter, error) {
 	c := &Converter{
 		FileName: rawConverter.FileName,
 		Package:  rawConverter.PackagePath,
@@ -145,13 +136,14 @@ func initConverter(loader *pkgload.PackageLoader, rawConverter *RawConverter) (*
 
 	if rawConverter.InterfaceName != "" {
 		c.ConverterConfig = DefaultConfigInterface
-		_, interfaceObj, err := loader.GetOneRaw(c.Package, rawConverter.InterfaceName)
+		_, interfaceObj, err := ctx.Loader.GetOneRaw(c.Package, rawConverter.InterfaceName)
 		if err != nil {
 			return nil, err
 		}
 
 		c.typ = interfaceObj.Type()
 		c.Name = rawConverter.InterfaceName + "Impl"
+		c.inferOutputPackage(ctx)
 		return c, nil
 	}
 
@@ -185,10 +177,14 @@ func parseConverterLine(ctx *context, c *Converter, value string) (err error) {
 	case "output:raw":
 		c.OutputRaw = append(c.OutputRaw, rest)
 	case configOutputFile:
+		if len(c.Extend) != 0 {
+			return fmt.Errorf("Cannot change output:file after extend functions have been added.\nMove the extend below the output:* setting.")
+		}
 		c.OutputFile, err = parse.File(ctx.WorkDir, rest)
+		c.inferOutputPackage(ctx)
 	case "output:format":
 		if len(c.Extend) != 0 {
-			return fmt.Errorf("Cannot change output:format after extend functions have been added.\nMove the extend below the output:format setting.")
+			return fmt.Errorf("Cannot change output:format after extend functions have been added.\nMove the extend below the output:* setting.")
 		}
 
 		c.OutputFormat, err = parse.Enum(false, rest, FormatFunction, FormatStruct, FormatVariable)
@@ -203,6 +199,11 @@ func parseConverterLine(ctx *context, c *Converter, value string) (err error) {
 			return fmt.Errorf("unsupported format for goverter:converter")
 		}
 	case "output:package":
+		if len(c.Extend) != 0 {
+			return fmt.Errorf("Cannot change output:package after extend functions have been added.\nMove the extend below the output:* setting.")
+		}
+		c.packageConfigured = true
+
 		c.OutputPackageName = ""
 		var pkg string
 		pkg, err = parse.String(rest)
@@ -215,6 +216,7 @@ func parseConverterLine(ctx *context, c *Converter, value string) (err error) {
 		case 1:
 			c.OutputPackagePath = parts[0]
 		}
+		c.inferOutputPackage(ctx)
 	case "struct:comment":
 		if err = c.requireStruct(); err != nil {
 			return err

docs/changelog.md

@@ -6,6 +6,10 @@ import GH from './GH.vue';
 
 ## unreleased
 
+- Allow unexported [`extend`](./reference/extend.md) functions with inferred
+  [`output:package`](./reference/output.md) from [`output:file`](./reference/output.md).
+  <GH issue="218" pr="219"/>
+
 ## v1.9.2
 
 - Fix comparison of signatures with aliases in

scenario/extend_external_unexported_same_package.yml

@@ -0,0 +1,33 @@
+input:
+    input.go: |
+        package execution
+
+        // goverter:converter
+        // goverter:output:file ./generated.go
+        // goverter:extend intToString
+        type Converter interface {
+            Convert(source Input) Output
+        }
+        func intToString(int) string {
+            return ""
+        }
+
+        type Input struct {
+            Age   int
+        }
+        type Output struct {
+            Age   string
+        }
+success:
+    - generated.go: |
+        // Code generated by github.com/jmattheis/goverter, DO NOT EDIT.
+
+        package execution
+
+        type ConverterImpl struct{}
+
+        func (c *ConverterImpl) Convert(source Input) Output {
+        	var executionOutput Output
+        	executionOutput.Age = intToString(source.Age)
+        	return executionOutput
+        }

scenario/fmtfunc_use_interface2.yml

@@ -26,4 +26,4 @@ error: |-
         github.com/jmattheis/goverter/execution.Converter
 
     Cannot change output:format after extend functions have been added.
-    Move the extend below the output:format setting.
+    Move the extend below the output:* setting.

scenario/into_source_package.yml

@@ -3,9 +3,9 @@ input:
         package structs
 
         // goverter:converter
-        // goverter:extend StringPToString
         // goverter:output:file ./generated.go
         // goverter:output:package github.com/jmattheis/goverter/execution:structs
+        // goverter:extend StringPToString
         type Converter interface {
             ConvertPerson(source Input) Output
         }

scenario/into_source_package_infer_full.yml

@@ -3,8 +3,8 @@ input:
         package structs
 
         // goverter:converter
-        // goverter:extend StringPToString
         // goverter:output:file ./generated.go
+        // goverter:extend StringPToString
         type Converter interface {
             ConvertPerson(source Input) Output
         }

scenario/into_source_package_infer_path.yml

@@ -3,9 +3,9 @@ input:
         package structs
 
         // goverter:converter
-        // goverter:extend StringPToString
         // goverter:output:file ./generated.go
         // goverter:output:package :structs
+        // goverter:extend StringPToString
         type Converter interface {
             ConvertPerson(source Input) Output
         }

scenario/output_package_mismatch_different_names.yml

@@ -0,0 +1,35 @@
+input:
+    input.go: |
+        package structs
+
+        // goverter:converter
+        // goverter:output:package pkg1:cde
+        type Converter interface {
+            Convert(source Input) Output
+        }
+
+        // goverter:converter
+        // goverter:output:package pkg1:abc
+        type Converter2 interface {
+            Convert(source Input) Output
+        }
+
+        type Input struct {
+            ID int
+        }
+        type Output struct {
+            ID int
+        }
+error: |-
+    Error creating converters
+        @workdir/input.go:5
+        github.com/jmattheis/goverter/execution.Converter
+    and
+        @workdir/input.go:11
+        github.com/jmattheis/goverter/execution.Converter2
+
+    Cannot use different packages
+        pkg1:cde
+        pkg1:abc
+    in the same output file:
+        @workdir/generated/generated.go

scenario/var_output_package_mismatch.yml

@@ -25,7 +25,7 @@ error: |-
         var definition
 
     Cannot use different packages
-        pkg2:structs
-        pkg1:structs
+        pkg2
+        pkg1
     in the same output file:
         @workdir/input.gen.go