support main package docs

cmd/docreflect/main.go

@@ -13,7 +13,7 @@ func main() {
 	}
 
 	packageName, args := args[0], args[1:]
-	if err := generate.GenerateRegistry(os.Stdout, packageName, args...); err != nil {
+	if err := generate.GenerateRegistry(generate.Options{}, os.Stdout, packageName, args...); err != nil {
 		log.Fatalln(err)
 	}
 }

generate/lib.go

@@ -27,10 +27,19 @@ Generated with https://code.squareroundforest.org/arpio/docreflect
 
 `
 
+// Options contains options for the generator.
+type Options struct {
+
+	// Main indicates that the docs for the symbols will be lookded up as part of the main package of an
+	// executable.
+	Main bool
+}
+
 type options struct {
 	wd      string
 	goroot  string
 	modules map[string]string
+	isMain  bool
 }
 
 func getGoroot() string {
@@ -544,7 +553,24 @@ func packageDocs(pkg *doc.Package) map[string]string {
 	)
 }
 
-func takeDocs(pkgs map[string][]*ast.Package, gopaths []string) (map[string]string, error) {
+func replacePath(p, prefix, replace string) string {
+	if !strings.HasPrefix(p, prefix) {
+		return p
+	}
+
+	return fmt.Sprintf("%s%s", replace, p[len(prefix):])
+}
+
+func replacePaths(m map[string]string, prefix, replace string) map[string]string {
+	var mm map[string]string
+	for p, d := range m {
+		mm = set(mm, replacePath(p, prefix, replace), d)
+	}
+
+	return mm
+}
+
+func takeDocs(o options, pkgs map[string][]*ast.Package, gopaths []string) (map[string]string, error) {
 	var dm map[string]string
 	for _, gp := range gopaths {
 		pp, _ := splitGopath(gp)
@@ -553,7 +579,12 @@ func takeDocs(pkgs map[string][]*ast.Package, gopaths []string) (map[string]stri
 			dpkg := doc.New(pkg, pp, doc.AllDecls|doc.PreserveAST)
 			*dpkg = fixDocPackage(*dpkg)
 			if isPackage {
-				dm = merge(dm, packageDocs(dpkg))
+				pd := packageDocs(dpkg)
+				if o.isMain {
+					pd = replacePaths(pd, pp, "main")
+				}
+
+				dm = merge(dm, pd)
 				continue
 			}
 
@@ -562,6 +593,10 @@ func takeDocs(pkgs map[string][]*ast.Package, gopaths []string) (map[string]stri
 				return nil, fmt.Errorf("symbol not found: %s", gp)
 			}
 
+			if o.isMain {
+				gp = replacePath(gp, pp, "main")
+			}
+
 			dm = set(dm, gp, sd)
 		}
 	}
@@ -583,7 +618,7 @@ func generate(o options, gopaths ...string) (map[string]string, error) {
 		return nil, err
 	}
 
-	return takeDocs(ppkgs, gopaths)
+	return takeDocs(o, ppkgs, gopaths)
 }
 
 func format(w io.Writer, pname string, docs map[string]string) error {
@@ -633,9 +668,10 @@ func format(w io.Writer, pname string, docs map[string]string) error {
 //
 // Some important gotchas to keep in mind, GenerateRegistry does not resolve type references like
 // type aliases, or type definitions based on named types, and it doesn't follow import paths.
-func GenerateRegistry(w io.Writer, outputPackageName string, gopath ...string) error {
-	o := initOptions()
-	d, err := generate(o, gopath...)
+func GenerateRegistry(o Options, w io.Writer, outputPackageName string, gopath ...string) error {
+	oo := initOptions()
+	oo.isMain = o.Main
+	d, err := generate(oo, gopath...)
 	if err != nil {
 		return err
 	}

generate/lib_test.go

@@ -86,6 +86,9 @@ func TestGenerate(t *testing.T) {
 		},
 	}
 
+	oMain := o
+	oMain.isMain = true
+
 	t.Run("generate", func(t *testing.T) {
 		t.Run(
 			"stdlib",
@@ -129,6 +132,20 @@ func TestGenerate(t *testing.T) {
 			),
 		)
 
+		t.Run(
+			"main",
+			testGenerate(
+				check(
+					"main", "Package testpackage is a test package",
+					"main.ExportedType", "ExportedType has docs",
+					"main.ExportedType.Bar.Baz", "Baz is another field",
+				),
+				"",
+				oMain,
+				packagePath,
+			),
+		)
+
 		t.Run("symbol", func(t *testing.T) {
 			t.Run("type", testGenerate(
 				check(