Include auto-generated files in recursive discovery by default

Fixes vektra#681

There are many legitimate use-cases where mockery needs to include auto-generated files
in its recursive package discovery. We add an `include-auto-generated` parameter that
is set to `true` by default, but can be set to `false` if users want to retain the
old behavior. We are considering the old behavior to be a bug due to the large number
of GitHub issues we'll likely get. The original motivation for adding this behavior
was fixed through a different mechanism, which is why we're considering this to be
a bugfix.

pkg/config/config.go

@@ -42,6 +42,7 @@ type Config struct {
 	DryRun               bool                   `mapstructure:"dry-run"`
 	Exported             bool                   `mapstructure:"exported"`
 	FileName             string                 `mapstructure:"filename"`
+	IncludeAutoGenerated bool                   `mapstructure:"include-auto-generated"`
 	InPackage            bool                   `mapstructure:"inpackage"`
 	InPackageSuffix      bool                   `mapstructure:"inpackage-suffix"`
 	KeepTree             bool                   `mapstructure:"keeptree"`
@@ -93,6 +94,7 @@ func NewConfigFromViper(v *viper.Viper) (*Config, error) {
 	} else {
 		v.SetDefault("dir", "mocks/{{.PackagePath}}")
 		v.SetDefault("filename", "mock_{{.InterfaceName}}.go")
+		v.SetDefault("include-auto-generated", true)
 		v.SetDefault("mockname", "Mock{{.InterfaceName}}")
 		v.SetDefault("outpkg", "{{.PackageName}}")
 		v.SetDefault("with-expecter", true)
@@ -429,6 +431,24 @@ func (c *Config) addSubPkgConfig(ctx context.Context, subPkgPath string, parentP
 	return nil
 }
 
+func isAutoGenerated(path *pathlib.Path) (bool, error) {
+	file, err := path.OpenFile(os.O_RDONLY)
+	if err != nil {
+		return false, stackerr.NewStackErr(err)
+	}
+	defer file.Close()
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		text := scanner.Text()
+		if strings.Contains(text, "DO NOT EDIT") {
+			return true, nil
+		} else if strings.HasPrefix(text, "package ") {
+			break
+		}
+	}
+	return false, nil
+}
+
 func (c *Config) subPackages(
 	ctx context.Context,
 	pkgPath string,
@@ -484,23 +504,18 @@ func (c *Config) subPackages(
 			return err
 		}
 
-		file, err := path.OpenFile(os.O_RDONLY)
-		if err != nil {
-			return err
-		}
-		defer file.Close()
-
 		_, haveVisitedDir := visitedDirs[path.Parent().String()]
 		if !haveVisitedDir && strings.HasSuffix(path.Name(), ".go") {
-			// Skip auto-generated files
-			scanner := bufio.NewScanner(file)
-			for scanner.Scan() {
-				text := scanner.Text()
-				if strings.Contains(text, "DO NOT EDIT") {
+
+			if !c.IncludeAutoGenerated {
+				autoGenerated, err := isAutoGenerated(path)
+				if err != nil {
+					log.Err(err).Stringer("path", path).Msg("failed to determine if file is auto-generated")
+					return err
+				}
+				if autoGenerated {
 					log.Debug().Stringer("path", path).Msg("skipping file as auto-generated")
 					return nil
-				} else if strings.HasPrefix(text, "package ") {
-					break
 				}
 			}
 

pkg/config/config_test.go

@@ -721,12 +721,13 @@ packages:
   github.com/vektra/mockery/v2/pkg:
 `,
 			want: &Config{
-				Dir:          "mocks/{{.PackagePath}}",
-				FileName:     "mock_{{.InterfaceName}}.go",
-				MockName:     "Mock{{.InterfaceName}}",
-				Outpkg:       "{{.PackageName}}",
-				WithExpecter: true,
-				LogLevel:     "info",
+				Dir:                  "mocks/{{.PackagePath}}",
+				FileName:             "mock_{{.InterfaceName}}.go",
+				IncludeAutoGenerated: true,
+				MockName:             "Mock{{.InterfaceName}}",
+				Outpkg:               "{{.PackageName}}",
+				WithExpecter:         true,
+				LogLevel:             "info",
 			},
 		},
 		{
@@ -738,12 +739,13 @@ packages:
   github.com/vektra/mockery/v2/pkg:
 `,
 			want: &Config{
-				Dir:          "barfoo",
-				FileName:     "foobar.go",
-				MockName:     "Mock{{.InterfaceName}}",
-				Outpkg:       "{{.PackageName}}",
-				WithExpecter: true,
-				LogLevel:     "info",
+				Dir:                  "barfoo",
+				FileName:             "foobar.go",
+				IncludeAutoGenerated: true,
+				MockName:             "Mock{{.InterfaceName}}",
+				Outpkg:               "{{.PackageName}}",
+				WithExpecter:         true,
+				LogLevel:             "info",
 			},
 		},
 	}
@@ -983,3 +985,51 @@ want
 		})
 	}
 }
+
+func Test_isAutoGenerated(t *testing.T) {
+	tests := []struct {
+		name    string
+		args    func(t *testing.T) *pathlib.Path
+		want    bool
+		wantErr bool
+	}{
+		{
+			name: "file is autogenerated",
+			args: func(t *testing.T) *pathlib.Path {
+				path := pathlib.NewPath(t.TempDir()).Join("file.go")
+				assert.NoError(t, path.WriteFile([]byte("// Code generated by mockery. DO NOT EDIT.")))
+				return path
+			},
+			want: true,
+		},
+		{
+			name: "file is not autogenerated",
+			args: func(t *testing.T) *pathlib.Path {
+				path := pathlib.NewPath(t.TempDir()).Join("file.go")
+				assert.NoError(t, path.WriteFile([]byte("package foobar")))
+				return path
+			},
+			want: false,
+		},
+		{
+			name: "error when reading file",
+			args: func(t *testing.T) *pathlib.Path {
+				path := pathlib.NewPath(t.TempDir()).Join("file.go")
+				return path
+			},
+			wantErr: true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := isAutoGenerated(tt.args(t))
+			if (err != nil) != tt.wantErr {
+				t.Errorf("isAutoGenerated() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if got != tt.want {
+				t.Errorf("isAutoGenerated() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}