codegen: add ability to insert comments and blank lines into the generated code

pkg/codegen/modelgenerate/generate_model.go

@@ -240,7 +240,7 @@ func GenerateSaveItemFunc(tbl schema.Table) *ast.FuncDecl {
 		List: func() []ast.Stmt {
 			ret := []ast.Stmt{}
 			if hasFks {
-				ret = append(ret, checkForeignKeyFailuresAssignment)
+				ret = append(ret, checkForeignKeyFailuresAssignment, BlankLine())
 			}
 			if hasUpdatedAt {
 				// Auto-timestamps: updated_at
@@ -261,7 +261,7 @@ func GenerateSaveItemFunc(tbl schema.Table) *ast.FuncDecl {
 					// Do create
 					List: append(
 						func() []ast.Stmt {
-							ret1 := []ast.Stmt{}
+							ret1 := []ast.Stmt{Comment("Do create")}
 							if hasCreatedAt {
 								// Auto-timestamps: created_at
 								ret1 = append(ret1, &ast.AssignStmt{
@@ -321,23 +321,25 @@ func GenerateSaveItemFunc(tbl schema.Table) *ast.FuncDecl {
 											},
 										},
 									},
-									Else: &ast.IfStmt{
-										Cond: &ast.BinaryExpr{
-											X:  ast.NewIdent("err"),
-											Op: token.NEQ,
-											Y:  ast.NewIdent("nil"),
-										},
-										Body: &ast.BlockStmt{
-											List: []ast.Stmt{
-												&ast.ExprStmt{
-													X: &ast.CallExpr{
-														Fun:  ast.NewIdent("panic"),
-														Args: []ast.Expr{ast.NewIdent("err")},
-													},
-												},
+									Else: func() *ast.IfStmt {
+										panicStmt := &ast.ExprStmt{
+											X: &ast.CallExpr{
+												Fun:  ast.NewIdent("panic"),
+												Args: []ast.Expr{ast.NewIdent("err")},
 											},
-										},
-									},
+										}
+										TrailingComments[panicStmt] = "not a foreign key error"
+										return &ast.IfStmt{
+											Cond: &ast.BinaryExpr{
+												X:  ast.NewIdent("err"),
+												Op: token.NEQ,
+												Y:  ast.NewIdent("nil"),
+											},
+											Body: &ast.BlockStmt{
+												List: []ast.Stmt{panicStmt},
+											},
+										}
+									}(),
 								},
 							)
 						}(),
@@ -357,6 +359,7 @@ func GenerateSaveItemFunc(tbl schema.Table) *ast.FuncDecl {
 				Else: &ast.BlockStmt{
 					// Do update
 					List: []ast.Stmt{
+						Comment("Do update"),
 						&ast.AssignStmt{
 							Lhs: []ast.Expr{ast.NewIdent("result")},
 							Tok: token.DEFINE,
@@ -389,6 +392,10 @@ func GenerateSaveItemFunc(tbl schema.Table) *ast.FuncDecl {
 	}
 
 	funcDecl := &ast.FuncDecl{
+		Doc: &ast.CommentGroup{List: []*ast.Comment{
+			{Text: fmt.Sprintf("// Save%s creates or updates a %s in the database.", tbl.GoTypeName, tbl.GoTypeName)},
+			{Text: "// If the item doesn't exist (has no ID set), it will create it; otherwise it will do an update."},
+		}},
 		Recv: dbRecv,
 		Name: ast.NewIdent("Save" + tbl.GoTypeName),
 		Type: &ast.FuncType{