fix: show filename in parse errors for imported files

internal/cmd/validate-test/yaml-with-zed-extension.zed

@@ -0,0 +1,15 @@
+---
+schema: |-
+  definition user {}
+
+  definition resource {
+    relation user: user
+    permission view = user
+  }
+relationships: >-
+  resource:1#user@user:1
+assertions:
+  assertTrue:
+    - "resource:1#user@user:1"
+  assertFalse:
+    - "resource:1#user@user:2"

internal/cmd/validate.go

@@ -169,6 +169,15 @@ func validateCmdFunc(cmd *cobra.Command, filenames []string) (string, bool, erro
 		case decode.FileTypeYaml:
 			parsed, err = d.UnmarshalYAMLValidationFile()
 		case decode.FileTypeZed:
+			if decode.LooksLikeYAMLValidationFile(string(d.Contents)) {
+				fmt.Fprintf(toPrint, "%sfile %q has a .zed extension but appears to be a YAML validation file.\n"+
+					"  Rename the file to use a .yaml extension, or use --type yaml to override:\n"+
+					"    zed validate %s --type yaml\n\n",
+					errorPrefix(), filename, filename,
+				)
+				shouldExit = true
+				continue
+			}
 			parsed = d.UnmarshalSchemaValidationFile()
 		default:
 			parsed, err = d.UnmarshalAsYAMLOrSchema()
@@ -306,7 +315,11 @@ func outputDeveloperErrorsWithLineOffset(sb *strings.Builder, validateContents [
 }
 
 func outputDeveloperError(sb *strings.Builder, devError *devinterface.DeveloperError, lines []string, lineOffset int) {
-	lineContext := fmt.Sprintf("parse error in `%s`, line %d, column %d:", devError.Context, devError.Line, devError.Column)
+	errorSource := devError.Context
+	if len(devError.Path) > 0 && devError.Path[0] != "" {
+		errorSource = devError.Path[0]
+	}
+	lineContext := fmt.Sprintf("parse error in `%s`, line %d, column %d:", errorSource, devError.Line, devError.Column)
 	fmt.Fprintf(sb, "%s%s %s\n", errorPrefix(), lineContext, errorMessageStyle().Render(devError.Message))
 	errorLineNumber := int(devError.Line) - 1 + lineOffset // devError.Line is 1-indexed
 	for i := errorLineNumber - 3; i < errorLineNumber+3; i++ {

internal/cmd/validate_test.go

@@ -97,7 +97,7 @@ total files: 2, successfully validated files: 2
 			},
 			expectStr: filepath.Join("validate-test", "standard-validation.yaml") + `
 Success! - 1 relationships loaded, 2 assertions run, 0 expected relations validated
-` + filepath.Join("validate-test", "invalid-schema.zed") + "\nerror: parse error in `something`, line 1, column 1: Unexpected token at root level: TokenTypeIdentifier                             \n 1 > something something {}\n   > ^~~~~~~~~\n 2 | \n\n\n",
+` + filepath.Join("validate-test", "invalid-schema.zed") + "\nerror: parse error in `invalid-schema.zed`, line 1, column 1: Unexpected token at root level: TokenTypeIdentifier                             \n 1 > something something {}\n   > ^~~~~~~~~\n 2 | \n\n\n",
 			expectNonZeroStatusCode: true,
 		},
 		`schema_only_passes`: {
@@ -116,7 +116,7 @@ Success! - 1 relationships loaded, 2 assertions run, 0 expected relations valida
 			files: []string{
 				filepath.Join("validate-test", "invalid-schema.zed"),
 			},
-			expectStr:               "error: parse error in `something`, line 1, column 1: Unexpected token at root level: TokenTypeIdentifier                             \n 1 > something something {}\n   > ^~~~~~~~~\n 2 | \n\n\n",
+			expectStr:               "error: parse error in `invalid-schema.zed`, line 1, column 1: Unexpected token at root level: TokenTypeIdentifier                             \n 1 > something something {}\n   > ^~~~~~~~~\n 2 | \n\n\n",
 			expectNonZeroStatusCode: true,
 		},
 		`without_schema_fails`: {
@@ -192,7 +192,7 @@ complete - 0 relationships loaded, 0 assertions run, 0 expected relations valida
 				filepath.Join("validate-test", "missing-relation.zed"),
 			},
 			expectNonZeroStatusCode: true,
-			expectStr: "error: parse error in `write`, line 2, column 21: relation/permission `write` not found under definition `test`                   \n" +
+			expectStr: "error: parse error in `missing-relation.zed`, line 2, column 21: relation/permission `write` not found under definition `test`                   \n" +
 				" 1 |  definition test {\n" +
 				" 2 >   permission view = write\n" +
 				"   >                     ^~~~~\n " +
@@ -204,7 +204,7 @@ complete - 0 relationships loaded, 0 assertions run, 0 expected relations valida
 				filepath.Join("validate-test", "missing-relation.yaml"),
 			},
 			expectNonZeroStatusCode: true,
-			expectStr: "error: parse error in `write`, line 4, column 21: relation/permission `write` not found under definition `test`                   \n" +
+			expectStr: "error: parse error in `missing-relation.yaml`, line 4, column 21: relation/permission `write` not found under definition `test`                   \n" +
 				"  6 |   definition user {}\n" +
 				"  7 |   definition test {\n" +
 				"  8 |     relation viewer: user\n" +
@@ -268,14 +268,21 @@ complete - 0 relationships loaded, 0 assertions run, 0 expected relations valida
 				filepath.Join("validate-test", "composable-schema-imports-file-with-error.zed"),
 			},
 			expectNonZeroStatusCode: true,
-			expectStr:               "error: parse error in `unknownrel`, line 5, column 23: relation/permission `unknownrel` not found under definition `group`             \n  2 | definition user {}\n  3 | \n  4 | definition group {\n  5 >     permission view = unknownrel\n    >                       ^~~~~~~~~~\n  6 | }\n  7 | \n\n\n",
+			expectStr:               "error: parse error in `composable-schema-imported-with-error.zed`, line 5, column 23: relation/permission `unknownrel` not found under definition `group`             \n  2 | definition user {}\n  3 | \n  4 | definition group {\n  5 >     permission view = unknownrel\n    >                       ^~~~~~~~~~\n  6 | }\n  7 | \n\n\n",
 		},
 		`yaml_with_composable_schemaFile_with_import_error`: {
 			files: []string{
 				filepath.Join("validate-test", "external-composable-with-error.yaml"),
 			},
 			expectNonZeroStatusCode: true,
-			expectStr:               "error: parse error in `unknownrel`, line 5, column 23: relation/permission `unknownrel` not found under definition `group`             \n 3 | definition group {\n 4 |     relation member: user\n 5 |     permission view = unknownrel\n 6 > }\n 7 | \n\n\n",
+			expectStr:               "error: parse error in `composable-schema-with-import-error-imported.zed`, line 5, column 23: relation/permission `unknownrel` not found under definition `group`             \n 3 | definition group {\n 4 |     relation member: user\n 5 |     permission view = unknownrel\n 6 > }\n 7 | \n\n\n",
+		},
+		`yaml_content_with_zed_extension_gives_hint`: {
+			files: []string{
+				filepath.Join("validate-test", "yaml-with-zed-extension.zed"),
+			},
+			expectStr:               "error: file \"" + filepath.Join("validate-test", "yaml-with-zed-extension.zed") + "\" has a .zed extension but appears to be a YAML validation file.\n  Rename the file to use a .yaml extension, or use --type yaml to override:\n    zed validate " + filepath.Join("validate-test", "yaml-with-zed-extension.zed") + " --type yaml\n\n",
+			expectNonZeroStatusCode: true,
 		},
 		`yaml_with_schemaFile_escape_attempt_fails`: {
 			files: []string{

internal/decode/decoder.go

@@ -152,7 +152,7 @@ func (d *Decoder) UnmarshalYAMLValidationFile() (*validationfile.ValidationFile,
 	inputString := string(d.Contents)
 
 	// Only attempt YAML unmarshaling if the input looks like a YAML validation file.
-	if !hasYAMLSchemaKey(inputString) && !hasYAMLSchemaFileKey(inputString) && !yamlRelationshipsKeyPattern.MatchString(inputString) {
+	if !LooksLikeYAMLValidationFile(inputString) {
 		return nil, fmt.Errorf("%w: input does not appear to be a YAML validation file", ErrInvalidYamlTryZed)
 	}
 
@@ -213,3 +213,10 @@ func hasYAMLSchemaKey(input string) bool {
 func hasYAMLSchemaFileKey(input string) bool {
 	return yamlSchemaFileKeyPattern.MatchString(input)
 }
+
+// LooksLikeYAMLValidationFile returns true if the input appears to be a YAML
+// validation file based on the presence of top-level YAML keys (schema:,
+// schemaFile:, or relationships:).
+func LooksLikeYAMLValidationFile(input string) bool {
+	return hasYAMLSchemaKey(input) || hasYAMLSchemaFileKey(input) || yamlRelationshipsKeyPattern.MatchString(input)
+}