internal/dinosql: Emit Querier interface (#240)

* internal/dinosql: Emit Querier interface

Author: kyleconroy

examples/ondeck/db.go

@@ -13,7 +13,8 @@
       "queries": "ondeck/query",
       "engine": "postgresql",
       "emit_json_tags": true,
-      "emit_prepared_queries": true
+      "emit_prepared_queries": true,
+      "emit_interface": true
     },
     {
       "path": "jets",

examples/sqlc.json

@@ -47,8 +47,9 @@ type PackageSettings struct {
 	Path                string     `json:"path"`
 	Schema              string     `json:"schema"`
 	Queries             string     `json:"queries"`
-	EmitPreparedQueries bool       `json:"emit_prepared_queries"`
+	EmitInterface       bool       `json:"emit_interface"`
 	EmitJSONTags        bool       `json:"emit_json_tags"`
+	EmitPreparedQueries bool       `json:"emit_prepared_queries"`
 	Overrides           []Override `json:"overrides"`
 }
 

internal/dinosql/config.go

@@ -920,6 +920,27 @@ func (q *Queries) WithTx(tx *sql.Tx) *Queries {
 		{{- end}}
 	}
 }
+
+{{if .EmitInterface }}
+type Querier interface {
+	{{- range .GoQueries}}
+	{{- if eq .Cmd ":one"}}
+	{{.MethodName}}(ctx context.Context, {{.Arg.Pair}}) ({{.Ret.Type}}, error)
+	{{- end}}
+	{{- if eq .Cmd ":many"}}
+	{{.MethodName}}(ctx context.Context, {{.Arg.Pair}}) ([]{{.Ret.Type}}, error)
+	{{- end}}
+	{{- if eq .Cmd ":exec"}}
+	{{.MethodName}}(ctx context.Context, {{.Arg.Pair}}) error
+	{{- end}}
+	{{- if eq .Cmd ":execrows"}}
+	{{.MethodName}}(ctx context.Context, {{.Arg.Pair}}) (int64, error)
+	{{- end}}
+	{{- end}}
+}
+
+var _ Querier = (*Queries)(nil)
+{{end}}
 `
 
 var modelsTmpl = `// Code generated by sqlc. DO NOT EDIT.
@@ -1084,6 +1105,7 @@ type tmplCtx struct {
 
 	EmitJSONTags        bool
 	EmitPreparedQueries bool
+	EmitInterface       bool
 }
 
 func LowerTitle(s string) string {
@@ -1110,8 +1132,9 @@ func Generate(r Generateable, settings GenerateSettings) (map[string]string, err
 
 	tctx := tmplCtx{
 		Settings:            settings,
-		EmitPreparedQueries: pkgConfig.EmitPreparedQueries,
+		EmitInterface:       pkgConfig.EmitInterface,
 		EmitJSONTags:        pkgConfig.EmitJSONTags,
+		EmitPreparedQueries: pkgConfig.EmitPreparedQueries,
 		Q:                   "`",
 		Package:             pkgName,
 		GoQueries:           r.GoQueries(settings),