internal/dinosql: Import needed types for Querier (#285)

Before this change, sqlc would generate a Querier interface without
importing the correct types. This is now fixed.

Author: kyleconroy

examples/ondeck/db.go

@@ -202,10 +202,88 @@ func Imports(r Generateable, settings GenerateSettings) func(string) [][]string
 			return ModelImports(r, settings)
 		}
 
+		if filename == "querier.go" {
+			return InterfaceImports(r, settings)
+		}
+
 		return QueryImports(r, settings, filename)
 	}
 }
 
+func InterfaceImports(r Generateable, settings GenerateSettings) [][]string {
+	gq := r.GoQueries(settings)
+	uses := func(name string) bool {
+		for _, q := range gq {
+			if !q.Ret.isEmpty() {
+				if strings.HasPrefix(q.Ret.Type(), name) {
+					return true
+				}
+			}
+			if !q.Arg.isEmpty() {
+				if strings.HasPrefix(q.Arg.Type(), name) {
+					return true
+				}
+			}
+		}
+		return false
+	}
+
+	std := map[string]struct{}{
+		"context": struct{}{},
+	}
+	if uses("sql.Null") {
+		std["database/sql"] = struct{}{}
+	}
+	if uses("json.RawMessage") {
+		std["encoding/json"] = struct{}{}
+	}
+	if uses("time.Time") {
+		std["time"] = struct{}{}
+	}
+	if uses("net.IP") {
+		std["net"] = struct{}{}
+	}
+
+	pkg := make(map[string]struct{})
+	overrideTypes := map[string]string{}
+	for _, o := range append(settings.Overrides, settings.PackageMap[r.PkgName()].Overrides...) {
+		if o.goBasicType {
+			continue
+		}
+		overrideTypes[o.goTypeName] = o.goPackage
+	}
+
+	_, overrideNullTime := overrideTypes["pq.NullTime"]
+	if uses("pq.NullTime") && !overrideNullTime {
+		pkg["github.com/lib/pq"] = struct{}{}
+	}
+	_, overrideUUID := overrideTypes["uuid.UUID"]
+	if uses("uuid.UUID") && !overrideUUID {
+		pkg["github.com/google/uuid"] = struct{}{}
+	}
+
+	// Custom imports
+	for goType, importPath := range overrideTypes {
+		if _, ok := std[importPath]; !ok && uses(goType) {
+			pkg[importPath] = struct{}{}
+		}
+	}
+
+	pkgs := make([]string, 0, len(pkg))
+	for p, _ := range pkg {
+		pkgs = append(pkgs, p)
+	}
+
+	stds := make([]string, 0, len(std))
+	for s, _ := range std {
+		stds = append(stds, s)
+	}
+
+	sort.Strings(stds)
+	sort.Strings(pkgs)
+	return [][]string{stds, pkgs}
+}
+
 func ModelImports(r Generateable, settings GenerateSettings) [][]string {
 	std := make(map[string]struct{})
 	if UsesType(r, "sql.Null", settings) {
@@ -903,8 +981,19 @@ func (q *Queries) WithTx(tx *sql.Tx) *Queries {
 		{{- end}}
 	}
 }
+`
+
+var ifaceTmpl = `// Code generated by sqlc. DO NOT EDIT.
+
+package {{.Package}}
+
+import (
+	{{range imports .SourceName}}
+	{{range .}}"{{.}}"
+	{{end}}
+	{{end}}
+)
 
-{{if .EmitInterface }}
 type Querier interface {
 	{{- range .GoQueries}}
 	{{- if eq .Cmd ":one"}}
@@ -923,7 +1012,6 @@ type Querier interface {
 }
 
 var _ Querier = (*Queries)(nil)
-{{end}}
 `
 
 var modelsTmpl = `// Code generated by sqlc. DO NOT EDIT.
@@ -1112,6 +1200,7 @@ func Generate(r Generateable, settings GenerateSettings) (map[string]string, err
 	dbFile := template.Must(template.New("table").Funcs(funcMap).Parse(dbTmpl))
 	modelsFile := template.Must(template.New("table").Funcs(funcMap).Parse(modelsTmpl))
 	sqlFile := template.Must(template.New("table").Funcs(funcMap).Parse(sqlTmpl))
+	ifaceFile := template.Must(template.New("table").Funcs(funcMap).Parse(ifaceTmpl))
 
 	tctx := tmplCtx{
 		Settings:            settings,
@@ -1154,6 +1243,11 @@ func Generate(r Generateable, settings GenerateSettings) (map[string]string, err
 	if err := execute("models.go", modelsFile); err != nil {
 		return nil, err
 	}
+	if pkgConfig.EmitInterface {
+		if err := execute("querier.go", ifaceFile); err != nil {
+			return nil, err
+		}
+	}
 
 	files := map[string]struct{}{}
 	for _, gq := range r.GoQueries(settings) {