oapi-codegen · jacklee1792 · Jul 1, 2022 · Nov 24, 2022
diff --git a/pkg/codegen/codegen.go b/pkg/codegen/codegen.go
@@ -18,8 +18,11 @@ import (
 	"bufio"
 	"bytes"
 	"embed"
+	"errors"
 	"fmt"
 	"io/fs"
+	"os"
+	"path"
 	"runtime/debug"
 	"sort"
 	"strings"
@@ -130,6 +133,36 @@ func Generate(spec *openapi3.T, opts Configuration) (string, error) {
 
 	// Override built-in templates with user-provided versions
 	for _, tpl := range t.Templates() {
+		// Check for template in provided template directory
+		if dir := opts.OutputOptions.UserTemplatesDir; dir != "" {
+			fp := path.Join(dir, tpl.Name())
+			_, err := os.Stat(fp)
+			if err != nil && !errors.Is(err, os.ErrNotExist) {
+				return "", fmt.Errorf("error accessing user-provided template %q: %w", fp, err)
+			}
+			if err == nil {
+				utpl := t.New(tpl.Name())
+				data, err := os.ReadFile(fp)
+				if err != nil {
+					return "", fmt.Errorf("error reading user-provided template %q: %w", fp, err)
+				}
+				if _, err := utpl.Parse(string(data)); err != nil {
+					return "", fmt.Errorf("error parsing user-provided template %q: %w", fp, err)
+				}
+			}
+		}
+		// Check for template in a provided file path
+		if fp, ok := opts.OutputOptions.UserTemplateFiles[tpl.Name()]; ok {
+			utpl := t.New(tpl.Name())
+			data, err := os.ReadFile(fp)
+			if err != nil {
+				return "", fmt.Errorf("error reading user-provided template %q: %w", fp, err)
+			}
+			if _, err := utpl.Parse(string(data)); err != nil {
+				return "", fmt.Errorf("error parsing user-provided template %q: %w", fp, err)
+			}
+		}
+		// Check for template provided inline in the configuration
 		if _, ok := opts.OutputOptions.UserTemplates[tpl.Name()]; ok {
 			utpl := t.New(tpl.Name())
 			if _, err := utpl.Parse(opts.OutputOptions.UserTemplates[tpl.Name()]); err != nil {

diff --git a/pkg/codegen/codegen_test.go b/pkg/codegen/codegen_test.go
@@ -3,18 +3,20 @@ package codegen
 import (
 	"bytes"
 	_ "embed"
+	"fmt"
 	"go/format"
 	"io"
 	"net/http"
 	"testing"
 
-	examplePetstoreClient "github.com/deepmap/oapi-codegen/examples/petstore-expanded"
-	examplePetstore "github.com/deepmap/oapi-codegen/examples/petstore-expanded/echo/api"
-	"github.com/deepmap/oapi-codegen/pkg/util"
 	"github.com/getkin/kin-openapi/openapi3"
 	"github.com/golangci/lint-1"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+
+	examplePetstoreClient "github.com/deepmap/oapi-codegen/examples/petstore-expanded"
+	examplePetstore "github.com/deepmap/oapi-codegen/examples/petstore-expanded/echo/api"
+	"github.com/deepmap/oapi-codegen/pkg/util"
 )
 
 const (
@@ -76,39 +78,68 @@ func TestExamplePetStoreCodeGeneration(t *testing.T) {
 }
 
 func TestExamplePetStoreCodeGenerationWithUserTemplates(t *testing.T) {
-
-	userTemplates := map[string]string{"typedef.tmpl": "//blah"}
-
 	// Input vars for code generation:
 	packageName := "api"
 	opts := Configuration{
 		PackageName: packageName,
 		Generate: GenerateOptions{
-			Models: true,
-		},
-		OutputOptions: OutputOptions{
-			UserTemplates: userTemplates,
+			ChiServer: true,
+			Models:    true,
 		},
 	}
 
-	// Get a spec from the example PetStore definition:
-	swagger, err := examplePetstore.GetSwagger()
-	assert.NoError(t, err)
-
-	// Run our code generation:
-	code, err := Generate(swagger, opts)
-	assert.NoError(t, err)
-	assert.NotEmpty(t, code)
-
-	// Check that we have valid (formattable) code:
-	_, err = format.Source([]byte(code))
-	assert.NoError(t, err)
-
-	// Check that we have a package:
-	assert.Contains(t, code, "package api")
-
-	// Check that the built-in template has been overriden
-	assert.Contains(t, code, "//blah")
+	for set := 0; set < 8; set++ {
+		var (
+			oo                   OutputOptions
+			useDirectoryOverride = set&4 != 0
+			useFileOverride      = set&2 != 0
+			useInlineOverride    = set&1 != 0
+		)
+		if useDirectoryOverride {
+			oo.UserTemplatesDir = "testdata"
+		}
+		if useFileOverride {
+			oo.UserTemplateFiles = map[string]string{"chi/chi-interface.tmpl": "testdata/chi-interface.tmpl"}
+		}
+		if useInlineOverride {
+			oo.UserTemplates = map[string]string{"chi/chi-interface.tmpl": "// inline override"}
+		}
+		opts.OutputOptions = oo
+
+		testName := fmt.Sprintf(
+			"override: directory=%v, file=%v, inline=%v",
+			useDirectoryOverride,
+			useFileOverride,
+			useInlineOverride,
+		)
+		t.Run(testName, func(t *testing.T) {
+			// Get a spec from the example PetStore definition:
+			swagger, err := examplePetstore.GetSwagger()
+			assert.NoError(t, err)
+
+			// Run our code generation:
+			code, err := Generate(swagger, opts)
+			assert.NoError(t, err)
+			assert.NotEmpty(t, code)
+
+			// Check that we have valid (formattable) code:
+			_, err = format.Source([]byte(code))
+			assert.NoError(t, err)
+
+			// Check that we have a package:
+			assert.Contains(t, code, "package api")
+
+			// Check that the generated code has the appropriate template override applied
+			switch {
+			case useInlineOverride:
+				assert.Contains(t, code, "// inline override")
+			case useFileOverride:
+				assert.Contains(t, code, "// file override")
+			case useDirectoryOverride:
+				assert.Contains(t, code, "// directory override")
+			}
+		})
+	}
 }
 
 func TestExamplePetStoreParseFunction(t *testing.T) {

diff --git a/pkg/codegen/configuration.go b/pkg/codegen/configuration.go
@@ -73,11 +73,13 @@ type CompatibilityOptions struct {
 
 // OutputOptions are used to modify the output code in some way.
 type OutputOptions struct {
-	SkipFmt       bool              `yaml:"skip-fmt,omitempty"`       // Whether to skip go imports on the generated code
-	SkipPrune     bool              `yaml:"skip-prune,omitempty"`     // Whether to skip pruning unused components on the generated code
-	IncludeTags   []string          `yaml:"include-tags,omitempty"`   // Only include operations that have one of these tags. Ignored when empty.
-	ExcludeTags   []string          `yaml:"exclude-tags,omitempty"`   // Exclude operations that have one of these tags. Ignored when empty.
-	UserTemplates map[string]string `yaml:"user-templates,omitempty"` // Override built-in templates from user-provided files
+	SkipFmt           bool              `yaml:"skip-fmt,omitempty"`            // Whether to skip go imports on the generated code
+	SkipPrune         bool              `yaml:"skip-prune,omitempty"`          // Whether to skip pruning unused components on the generated code
+	IncludeTags       []string          `yaml:"include-tags,omitempty"`        // Only include operations that have one of these tags. Ignored when empty.
+	ExcludeTags       []string          `yaml:"exclude-tags,omitempty"`        // Exclude operations that have one of these tags. Ignored when empty.
+	UserTemplates     map[string]string `yaml:"user-templates,omitempty"`      // Override built-in templates from user-provided files
+	UserTemplateFiles map[string]string `yaml:"user-template-files,omitempty"` // Same as UserTemplates, with filenames as values instead
+	UserTemplatesDir  string            `yaml:"user-templates-dir,omitempty"`
 
 	ExcludeSchemas     []string `yaml:"exclude-schemas,omitempty"`      // Exclude from generation schemas with given names. Ignored when empty.
 	ResponseTypeSuffix string   `yaml:"response-type-suffix,omitempty"` // The suffix used for responses types

diff --git a/pkg/codegen/testdata/chi-interface.tmpl b/pkg/codegen/testdata/chi-interface.tmpl
@@ -0,0 +1 @@
+// file override
diff --git a/pkg/codegen/testdata/chi/chi-interface.tmpl b/pkg/codegen/testdata/chi/chi-interface.tmpl
@@ -0,0 +1 @@
+// directory override