config: Allow loading of .regal.yaml file too (#1339)

* config: Allow loading of .regal.yaml file too

Fixes #1288

Signed-off-by: Charlie Egan <[email protected]>

* config: Choose most specific file

Signed-off-by: Charlie Egan <[email protected]>

* Markdown line length lint

* / -> or

---------

Signed-off-by: Charlie Egan <[email protected]>

README.md

@@ -342,7 +342,7 @@ levels are available:
 Additionally, some rules may have configuration options of their own. See the documentation page for a rule to learn
 more about it.
 
-**.regal/config.yaml**
+**.regal/config.yaml** or **.regal.yaml**
 ```yaml
 rules:
   style:
@@ -400,12 +400,15 @@ project:
       rego-version: 0
 ```
 
-Regal will automatically search for a configuration file (`.regal/config.yaml`) in the current directory, and if not
-found, traverse the parent directories either until either one is found, or the top of the directory hierarchy is
-reached. If no configuration file is found, Regal will use the default configuration.
+Regal will automatically search for a configuration file (`.regal/config.yaml`
+or `.regal.yaml`) in the current directory, and if not found, traverse the
+parent directories either until either one is found, or the top of the directory
+hierarchy is reached. If no configuration file is found, Regal will use the
+default configuration.
 
-A custom configuration may be also be provided using the `--config-file`/`-c` option for `regal lint`, which when
-provided will be used to override the default configuration.
+A custom configuration may be also be provided using the `--config-file`/`-c`
+option for `regal lint`, which when provided will be used to override the
+default configuration.
 
 ## Ignoring Rules
 

cmd/languageserver.go

@@ -38,7 +38,7 @@ func init() {
 				} else {
 					fmt.Fprintf(
 						os.Stderr,
-						"Regal Language Server (path: %s, version: %s)",
+						"Regal Language Server (path: %s, version: %s)\n",
 						absPath,
 						cmp.Or(version.Version, "Unknown"),
 					)

docs/remote-features.md

@@ -23,5 +23,5 @@ GitHub API rate limits when using Regal.
 
 This functionality can be disabled in two ways:
 
-* Using `.regal/config.yaml`: set `features.remote.check-version` to `false`.
+* Using `.regal/config.yaml` / `.regal.yaml`: set `features.remote.check-version` to `false`.
 * Using an environment variable: set `REGAL_DISABLE_CHECK_VERSION` to `true`.

docs/rules/imports/use-rego-v1.md

@@ -71,7 +71,7 @@ been disabled due to missing capabilities, kindly reminding you of them, but wit
 In the example below we're using the capabilities setting to target OPA v0.55.0 (where `import rego.v1` is not
 available):
 
-**.regal/config.yaml**
+**.regal/config.yaml** or **.regal.yaml**
 ```yaml
 capabilities:
   from:

internal/lsp/server.go

@@ -2526,7 +2526,10 @@ func (l *LanguageServer) handleInitialize(
 
 		configFile, err := config.FindConfig(workspaceRootPath)
 		if err == nil {
+			l.logf(log.LevelMessage, "using config file: %s", configFile.Name())
 			l.configWatcher.Watch(configFile.Name())
+		} else {
+			l.logf(log.LevelMessage, "no config file found in workspace: %s", err)
 		}
 
 		if _, err = l.loadWorkspaceContents(ctx, false); err != nil {

pkg/config/config.go

@@ -118,20 +118,66 @@ type Builtin struct {
 }
 
 const (
-	regalDirName   = ".regal"
-	configFileName = "config.yaml"
+	regalDirName             = ".regal"
+	configFileName           = "config.yaml"
+	standaloneConfigFileName = ".regal.yaml"
 )
 
-// FindRegalDirectory searches for a .regal directory first in the directory of path, and if not found,
-// in the parent directory, and if not found, in the parent's parent directory, and so on.
-func FindRegalDirectory(path string) (*os.File, error) {
+// FindConfig attempts to find either the .regal directory or .regal.yaml
+// config file, and returns the appropriate file or an error.
+func FindConfig(path string) (*os.File, error) {
+	regalDir, regalDirError := FindRegalDirectory(path)
+	regalConfigFile, regalConfigFileError := FindRegalConfigFile(path)
+
+	var regalDirParent, regalConfigFileParent string
+	if regalDirError == nil && regalConfigFileError == nil {
+		regalDirParent = filepath.Dir(regalDir.Name())
+		regalConfigFileParent = filepath.Dir(regalConfigFile.Name())
+
+		if regalDirParent == regalConfigFileParent {
+			return nil, errors.New("conflicting config files: both .regal directory and .regal.yaml found")
+		}
+	}
+
+	if regalDirError != nil && regalConfigFileError != nil {
+		return nil, errors.New("could not find Regal config")
+	}
+
+	// if the config file parent is not "", then it was found, and if it's
+	// longer then it's more specific to the search path in question, and so we
+	// return that here in such cases.
+	if len(regalConfigFileParent) > len(regalDirParent) {
+		return regalConfigFile, nil
+	}
+
+	// if there is a .regal directory, when a config file is expected to be
+	// found inside.
+	if regalDirError == nil {
+		expectedConfigFilePath := filepath.Join(regalDir.Name(), rio.PathSeparator, configFileName)
+
+		_, err := os.Stat(expectedConfigFilePath)
+		if err != nil && os.IsNotExist(err) {
+			return nil, errors.New("config file was not found in .regal directory")
+		} else if err != nil {
+			return nil, fmt.Errorf("failed to stat .regal config file: %w", err)
+		}
+
+		return os.Open(expectedConfigFilePath) //nolint:wrapcheck
+	}
+
+	// regalConfigFileError is nil at this point, so we can return the file
+	return regalConfigFile, nil
+}
+
+// findUpwards searches for a file or directory matching the given name,
+// starting from the provided path and moving upwards.
+func findUpwards(path, name string, expectDir bool) (*os.File, error) {
 	finfo, err := os.Stat(path)
 	if err != nil {
 		return nil, fmt.Errorf("failed to stat path %v: %w", path, err)
 	}
 
 	dir := path
-
 	if !finfo.IsDir() {
 		dir = filepath.Dir(path)
 	}
@@ -142,33 +188,31 @@ func FindRegalDirectory(path string) (*os.File, error) {
 	for {
 		var searchPath string
 		if volume == "" {
-			searchPath = filepath.Join(rio.PathSeparator, dir, regalDirName)
+			searchPath = filepath.Join(rio.PathSeparator, dir, name)
 		} else {
-			searchPath = filepath.Join(dir, regalDirName)
+			searchPath = filepath.Join(dir, name)
 		}
 
-		regalDir, err := os.Open(searchPath)
+		file, err := os.Open(searchPath)
 		if err == nil {
-			rdInfo, err := regalDir.Stat()
-			if err == nil && rdInfo.IsDir() {
-				return regalDir, nil
+			fileInfo, err := file.Stat()
+			if err == nil && fileInfo.IsDir() == expectDir {
+				return file, nil
 			}
 		}
 
-		if searchPath == volume+rio.PathSeparator+regalDirName {
+		if searchPath == volume+rio.PathSeparator+name {
 			// Stop traversing at the root path
 			return nil, fmt.Errorf("can't traverse past root directory %w", err)
 		}
 
 		// Move up one level in the directory tree
 		parts := strings.Split(dir, rio.PathSeparator)
-
 		if len(parts) < 2 {
 			return nil, errors.New("stopping as dir is root directory")
 		}
 
 		parts = parts[:len(parts)-1]
-
 		if parts[0] == volume {
 			parts[0] = volume + rio.PathSeparator
 		}
@@ -177,6 +221,16 @@ func FindRegalDirectory(path string) (*os.File, error) {
 	}
 }
 
+// FindRegalDirectory searches for a .regal directory upwards from the provided path.
+func FindRegalDirectory(path string) (*os.File, error) {
+	return findUpwards(path, regalDirName, true)
+}
+
+// FindRegalConfigFile searches for a .regal.yaml config file upwards from the provided path.
+func FindRegalConfigFile(path string) (*os.File, error) {
+	return findUpwards(path, standaloneConfigFileName, false)
+}
+
 // FindBundleRootDirectories finds all bundle root directories from the provided path,
 // which **must** be an absolute path. Bundle root directories may be found either by:
 //
@@ -285,15 +339,6 @@ func rootsFromRegalDirectory(regalDir *os.File) ([]string, error) {
 	return foundBundleRoots, nil
 }
 
-func FindConfig(path string) (*os.File, error) {
-	regalDir, err := FindRegalDirectory(path)
-	if err != nil {
-		return nil, fmt.Errorf("could not find .regal directory: %w", err)
-	}
-
-	return os.Open(filepath.Join(regalDir.Name(), rio.PathSeparator, configFileName)) //nolint:wrapcheck
-}
-
 func FromMap(confMap map[string]any) (Config, error) {
 	var conf Config
 

pkg/config/config_test.go

@@ -5,6 +5,7 @@ import (
 	"os"
 	"path/filepath"
 	"slices"
+	"strings"
 	"testing"
 
 	"gopkg.in/yaml.v3"
@@ -54,32 +55,93 @@ func TestFindRegalDirectory(t *testing.T) {
 func TestFindConfig(t *testing.T) {
 	t.Parallel()
 
-	fs := map[string]string{
-		"/foo/bar/baz/p.rego":         "",
-		"/foo/bar/.regal/config.yaml": "",
+	testCases := map[string]struct {
+		FS           map[string]string
+		Error        string
+		ExpectedName string
+	}{
+		"no config file": {
+			FS: map[string]string{
+				"/foo/bar/baz/p.rego": "",
+				"/foo/bar/bax.json":   "",
+			},
+			Error: "could not find Regal config",
+		},
+		".regal/config.yaml": {
+			FS: map[string]string{
+				"/foo/bar/baz/p.rego":         "",
+				"/foo/bar/.regal/config.yaml": "",
+			},
+			ExpectedName: "/foo/bar/.regal/config.yaml",
+		},
+		".regal/ dir missing config file": {
+			FS: map[string]string{
+				"/foo/bar/baz/p.rego":   "",
+				"/foo/bar/.regal/.keep": "", // .keep file to ensure the dir is present
+			},
+			Error: "config file was not found in .regal directory",
+		},
+		".regal.yaml": {
+			FS: map[string]string{
+				"/foo/bar/baz/p.rego":  "",
+				"/foo/bar/.regal.yaml": "",
+			},
+			ExpectedName: "/foo/bar/.regal.yaml",
+		},
+		".regal.yaml and .regal/config.yaml": {
+			FS: map[string]string{
+				"/foo/bar/baz/p.rego":         "",
+				"/foo/bar/.regal.yaml":        "",
+				"/foo/bar/.regal/config.yaml": "",
+			},
+			Error: "conflicting config files: both .regal directory and .regal.yaml found",
+		},
+		".regal.yaml with .regal/config.yaml at higher directory": {
+			FS: map[string]string{
+				"/foo/bar/baz/p.rego":  "",
+				"/foo/bar/.regal.yaml": "",
+				"/.regal/config.yaml":  "",
+			},
+			ExpectedName: "/foo/bar/.regal.yaml",
+		},
+		".regal/config.yaml with .regal.yaml at higher directory": {
+			FS: map[string]string{
+				"/foo/bar/baz/p.rego":         "",
+				"/foo/bar/.regal/config.yaml": "",
+				"/.regal.yaml":                "",
+			},
+			ExpectedName: "/foo/bar/.regal/config.yaml",
+		},
 	}
 
-	test.WithTempFS(fs, func(root string) {
-		path := filepath.Join(root, "/foo/bar/baz")
+	for testName, testData := range testCases {
+		t.Run(testName, func(t *testing.T) {
+			t.Parallel()
 
-		if _, err := FindConfig(path); err != nil {
-			t.Error(err)
-		}
-	})
+			test.WithTempFS(testData.FS, func(root string) {
+				path := filepath.Join(root, "/foo/bar/baz")
 
-	fs = map[string]string{
-		"/foo/bar/baz/p.rego": "",
-		"/foo/bar/bax.json":   "",
-	}
+				configFile, err := FindConfig(path)
+				if testData.Error != "" {
+					if err == nil {
+						t.Fatalf("expected error %s, got nil", testData.Error)
+					}
 
-	test.WithTempFS(fs, func(root string) {
-		path := filepath.Join(root, "/foo/bar/baz")
+					if !strings.Contains(err.Error(), testData.Error) {
+						t.Fatalf("expected error %q, got %q", testData.Error, err.Error())
+					}
+				} else if err != nil {
+					t.Fatalf("expected no error, got %s", err)
+				}
 
-		_, err := FindConfig(path)
-		if err == nil {
-			t.Errorf("expected no config file to be found")
-		}
-	})
+				if testData.ExpectedName != "" {
+					if got, exp := strings.TrimPrefix(configFile.Name(), root), testData.ExpectedName; got != exp {
+						t.Fatalf("expected config file %q, got %q", exp, got)
+					}
+				}
+			})
+		})
+	}
 }
 
 func TestFindBundleRootDirectories(t *testing.T) {