feat: add "use_interface_return_types" option

docs/reference/config.md

@@ -141,6 +141,8 @@ The `gen` mapping supports the following keys:
   - If true, include support for prepared queries. Defaults to `false`.
 - `emit_interface`:
   - If true, output a `Querier` interface in the generated package. Defaults to `false`.
+- `use_interface_return_types`:
+  - If true, output will use the `Querier` interface as the return type the methods in the generated package. Defaults to `false`.
 - `emit_exact_table_names`:
   - If true, struct names will mirror table names. Otherwise, sqlc attempts to singularize plural table names. Defaults to `false`.
 - `emit_empty_slices`:

internal/codegen/golang/gen.go

@@ -39,6 +39,7 @@ type tmplCtx struct {
 	EmitAllEnumValues         bool
 	UsesCopyFrom              bool
 	UsesBatch                 bool
+	UseInterfaceReturnTypes   bool
 	OmitSqlcVersion           bool
 	BuildTags                 string
 }
@@ -169,6 +170,7 @@ func generate(req *plugin.GenerateRequest, options *opts.Options, enums []Enum,
 
 	tctx := tmplCtx{
 		EmitInterface:             options.EmitInterface,
+		UseInterfaceReturnTypes:   options.UseInterfaceReturnTypes,
 		EmitJSONTags:              options.EmitJsonTags,
 		JsonTagsIDUppercase:       options.JsonTagsIdUppercase,
 		EmitDBTags:                options.EmitDbTags,

internal/codegen/golang/imports.go

@@ -268,6 +268,16 @@
 
 	std["context"] = struct{}{}
 
+	sqlpkg := parseDriver(i.Options.SqlPackage)
+	switch sqlpkg {
+	case SQLDriverPGXV4:
+		pkg[ImportSpec{Path: "github.com/jackc/pgx/v4"}] = struct{}{}
+	case SQLDriverPGXV5:
+		pkg[ImportSpec{Path: "github.com/jackc/pgx/v5"}] = struct{}{}
+	default:
+		std["database/sql"] = struct{}{}
+	}
+
 	return sortedImports(std, pkg)
 }
 

internal/codegen/golang/opts/options.go

@@ -11,6 +11,7 @@ import (
 
 type Options struct {
 	EmitInterface               bool              `json:"emit_interface" yaml:"emit_interface"`
+	UseInterfaceReturnTypes     bool              `json:"use_interface_return_types" yaml:"use_interface_return_types"`
 	EmitJsonTags                bool              `json:"emit_json_tags" yaml:"emit_json_tags"`
 	JsonTagsIdUppercase         bool              `json:"json_tags_id_uppercase" yaml:"json_tags_id_uppercase"`
 	EmitDbTags                  bool              `json:"emit_db_tags" yaml:"emit_db_tags"`

internal/codegen/golang/templates/pgx/dbCode.tmpl

@@ -28,7 +28,11 @@ type Queries struct {
 }
 
 {{if not .EmitMethodsWithDBArgument}}
+{{- if and .EmitInterface .UseInterfaceReturnTypes}}
+func (q *Queries) WithTx(tx pgx.Tx) Querier {
+{{- else -}}
 func (q *Queries) WithTx(tx pgx.Tx) *Queries {
+{{- end}}
 	return &Queries{
 		db: tx,
 	}

internal/codegen/golang/templates/pgx/interfaceCode.tmpl

@@ -1,5 +1,10 @@
 {{define "interfaceCodePgx"}}
     type Querier interface {
+    {{- if .UseInterfaceReturnTypes}}
+        WithTx(tx pgx.Tx) Querier
+    {{- else -}}
+        WithTx(tx pgx.Tx) *Queries
+    {{- end}}
     {{- $dbtxParam := .EmitMethodsWithDBArgument -}}
     {{- range .GoQueries}}
         {{- if and (eq .Cmd ":one") ($dbtxParam) }}

internal/codegen/golang/templates/stdlib/dbCode.tmpl

@@ -90,7 +90,11 @@ type Queries struct {
 }
 
 {{if not .EmitMethodsWithDBArgument}}
+{{- if and .EmitInterface .UseInterfaceReturnTypes}}
+func (q *Queries) WithTx(tx *sql.Tx) Querier {
+{{- else -}}
 func (q *Queries) WithTx(tx *sql.Tx) *Queries {
+{{- end}}
 	return &Queries{
 		db: tx,
      	{{- if .EmitPreparedQueries}}

internal/codegen/golang/templates/stdlib/interfaceCode.tmpl

@@ -1,5 +1,12 @@
 {{define "interfaceCodeStd"}}
     type Querier interface {
+    {{if not .EmitMethodsWithDBArgument}}
+    {{- if .UseInterfaceReturnTypes}}
+        WithTx(tx *sql.Tx) Querier
+    {{- else -}}
+        WithTx(tx *sql.Tx) *Queries
+    {{- end}}
+    {{- end}}
     {{- $dbtxParam := .EmitMethodsWithDBArgument -}}
     {{- range .GoQueries}}
         {{- if and (eq .Cmd ":one") ($dbtxParam) }}

internal/config/v_one.go

@@ -28,6 +28,7 @@ type v1PackageSettings struct {
 	Schema                    Paths             `json:"schema" yaml:"schema"`
 	Queries                   Paths             `json:"queries" yaml:"queries"`
 	EmitInterface             bool              `json:"emit_interface" yaml:"emit_interface"`
+	UseInterfaceReturnTypes   bool              `json:"use_interface_return_types" yaml:"use_interface_return_types"`
 	EmitJSONTags              bool              `json:"emit_json_tags" yaml:"emit_json_tags"`
 	JsonTagsIDUppercase       bool              `json:"json_tags_id_uppercase" yaml:"json_tags_id_uppercase"`
 	EmitDBTags                bool              `json:"emit_db_tags" yaml:"emit_db_tags"`
@@ -138,6 +139,7 @@ func (c *V1GenerateSettings) Translate() Config {
 			Gen: SQLGen{
 				Go: &golang.Options{
 					EmitInterface:             pkg.EmitInterface,
+					UseInterfaceReturnTypes:   pkg.UseInterfaceReturnTypes,
 					EmitJsonTags:              pkg.EmitJSONTags,
 					JsonTagsIdUppercase:       pkg.JsonTagsIDUppercase,
 					EmitDbTags:                pkg.EmitDBTags,

internal/config/v_one.json

@@ -92,6 +92,9 @@
                     "emit_interface": {
                         "type": "boolean"
                     },
+                    "use_interface_return_types": {
+                        "type": "boolean"
+                    },
                     "emit_json_tags": {
                         "type": "boolean"
                     },

internal/config/v_two.json

@@ -101,6 +101,9 @@
                                     "emit_interface": {
                                         "type": "boolean"
                                     },
+                                    "use_interface_return_types": {
+                                        "type": "boolean"
+                                    },
                                     "emit_json_tags": {
                                         "type": "boolean"
                                     },