[-] fix duplicate source names in YAML configs, fixes #630 (#633)

* [+] fix duplicate names in source file or source directory error handling
* [+] add `Sources.Validate()` to check correctness of sources imported

---------

Co-authored-by: Pavlo Golub <[email protected]>

Author: amrdb

internal/sources/types.go

@@ -2,6 +2,7 @@ package sources
 
 import (
 	"context"
+	"fmt"
 	"maps"
 	"reflect"
 	"slices"
@@ -65,6 +66,20 @@ type (
 	Sources []Source
 )
 
+func (srcs Sources) Validate() (Sources, error) {
+	names := map[string]any{}
+	for _, src := range srcs {
+		if _, ok := names[src.Name]; ok {
+			return nil, fmt.Errorf("duplicate source with name '%s' found", src.Name)
+		}
+		names[src.Name] = nil
+		if src.Kind == "" {
+			src.Kind = SourcePostgres
+		}
+	}
+	return srcs, nil
+}
+
 func (s *Source) GetDatabaseName() string {
 	if с, err := pgx.ParseConfig(s.ConnStr); err == nil {
 		return с.Database

internal/sources/yaml.go

@@ -81,7 +81,7 @@ func (fcr *fileSourcesReaderWriter) GetSources() (dbs Sources, err error) {
 	if err != nil {
 		return nil, err
 	}
-	return
+	return dbs.Validate()
 }
 
 func (fcr *fileSourcesReaderWriter) getSources(configFilePath string) (dbs Sources, err error) {
@@ -94,9 +94,6 @@ func (fcr *fileSourcesReaderWriter) getSources(configFilePath string) (dbs Sourc
 		return
 	}
 	for _, v := range c {
-		if v.Kind == "" {
-			v.Kind = SourcePostgres
-		}
 		dbs = append(dbs, fcr.expandEnvVars(v))
 	}
 	return

internal/sources/yaml_test.go

@@ -72,6 +72,51 @@ func TestYAMLGetMonitoredDatabases(t *testing.T) {
 		a.Error(err)
 		a.Nil(dbs)
 	})
+
+	t.Run("duplicate in single file", func(t *testing.T) {
+		tmpFile := filepath.Join(t.TempDir(), "duplicate.yaml")
+		yamlContent := `
+- name: test1
+  conn_str: postgresql://localhost/test1
+- name: test2
+  conn_str: postgresql://localhost/test2
+- name: test1
+  conn_str: postgresql://localhost/test1_duplicate
+`
+		err := os.WriteFile(tmpFile, []byte(yamlContent), 0644)
+		a.NoError(err)
+		yamlrw, err := sources.NewYAMLSourcesReaderWriter(ctx, tmpFile)
+		a.NoError(err)
+
+		dbs, err := yamlrw.GetSources()
+		a.Error(err)
+		a.Nil(dbs)
+	})
+
+	t.Run("duplicates across files", func(t *testing.T) {
+		tmpDir := t.TempDir()
+		yamlContent1 := `
+- name: test1
+  conn_str: postgresql://localhost/test1
+- name: test2
+  conn_str: postgresql://localhost/test2
+`
+		err := os.WriteFile(filepath.Join(tmpDir, "sources1.yaml"), []byte(yamlContent1), 0644)
+		a.NoError(err)
+
+		yamlContent2 := `
+- name: test1
+  conn_str: postgresql://localhost/test1_duplicate
+`
+		err = os.WriteFile(filepath.Join(tmpDir, "sources2.yaml"), []byte(yamlContent2), 0644)
+		a.NoError(err)
+		yamlrw, err := sources.NewYAMLSourcesReaderWriter(ctx, tmpDir)
+		a.NoError(err)
+
+		dbs, err := yamlrw.GetSources()
+		a.Error(err)
+		a.Nil(dbs)
+	})
 }
 
 func TestYAMLDeleteDatabase(t *testing.T) {