From 04300244a97203e3f568badc295dd65cac01996f Mon Sep 17 00:00:00 2001
From: Marc Izquierdo <marc.izquierdo@teamwork.com>
Date: Tue, 21 Apr 2026 11:04:02 +0200
Subject: [PATCH] Reduce cyclomatic complexity of fieldToSchema()

---
 docparse/jsonschema.go | 54 +++++++++++++++++++-----------------------
 1 file changed, 24 insertions(+), 30 deletions(-)

diff --git a/docparse/jsonschema.go b/docparse/jsonschema.go
index b539b96..bfc76eb 100644
--- a/docparse/jsonschema.go
+++ b/docparse/jsonschema.go
@@ -214,6 +214,24 @@ func setTags(name, fName string, p *Schema, tags []string) error {
 	return nil
 }
 
+// extractGenericIdent resolves the type expression on the left-hand side of a
+// generic instantiation (e.g. Foo[T] or pkg.Foo[T]) to its identifier and
+// package name.
+func extractGenericIdent(x ast.Expr, curPkg string) (*ast.Ident, string, error) {
+	switch x := x.(type) {
+	case *ast.Ident:
+		return x, curPkg, nil
+	case *ast.SelectorExpr:
+		pkgSel, ok := x.X.(*ast.Ident)
+		if !ok {
+			return nil, "", fmt.Errorf("unknown generic type selector: %T", x.X)
+		}
+		return x.Sel, pkgSel.Name, nil
+	default:
+		return nil, "", fmt.Errorf("unknown generic type: %T", x)
+	}
+}
+
 // Convert a struct field to JSON schema.
 func fieldToSchema(
 	prog *Program,
@@ -459,21 +477,9 @@ start:
 
 	// Generic types
 	case *ast.IndexExpr:
-		var genericsPkg string
-		var genericsIdent *ast.Ident
-		switch x := typ.X.(type) {
-		case *ast.Ident:
-			genericsIdent = x
-			genericsPkg = ref.Package
-		case *ast.SelectorExpr:
-			pkgSel, ok := x.X.(*ast.Ident)
-			if !ok {
-				return nil, fmt.Errorf("unknown generic type selector: %T", x.X)
-			}
-			genericsIdent = x.Sel
-			genericsPkg = pkgSel.Name
-		default:
-			return nil, fmt.Errorf("unknown generic type: %T", typ.X)
+		genericsIdent, genericsPkg, err := extractGenericIdent(typ.X, ref.Package)
+		if err != nil {
+			return nil, err
 		}
 		if mapped, err := genericMapTypeLookup(prog, &p, genericsPkg, genericsIdent.Name, ref, typ.Index); err != nil {
 			return nil, err
@@ -486,21 +492,9 @@ start:
 		return &p, nil
 
 	case *ast.IndexListExpr:
-		var genericsPkg string
-		var genericsIdent *ast.Ident
-		switch x := typ.X.(type) {
-		case *ast.Ident:
-			genericsIdent = x
-			genericsPkg = ref.Package
-		case *ast.SelectorExpr:
-			pkgSel, ok := x.X.(*ast.Ident)
-			if !ok {
-				return nil, fmt.Errorf("unknown generic type selector: %T", x.X)
-			}
-			genericsIdent = x.Sel
-			genericsPkg = pkgSel.Name
-		default:
-			return nil, fmt.Errorf("unknown generic type: %T", typ.X)
+		genericsIdent, genericsPkg, err := extractGenericIdent(typ.X, ref.Package)
+		if err != nil {
+			return nil, err
 		}
 		if mapped, err := genericMapTypeLookup(prog, &p, genericsPkg, genericsIdent.Name, ref, typ.Indices...); err != nil {
 			return nil, err