cmd/config: add migration edge case tests

Cover idempotency, backup creation, non-empty legacy directory
preservation, and save writing to the new path after migration.

cmd/config/config.go

@@ -3,9 +3,11 @@
 package config
 
 import (
+	"bytes"
 	"encoding/json"
 	"errors"
 	"fmt"
+	"log/slog"
 	"os"
 	"path/filepath"
 	"strings"
@@ -20,6 +22,14 @@ type config struct {
 }
 
 func configPath() (string, error) {
+	home, err := os.UserHomeDir()
+	if err != nil {
+		return "", err
+	}
+	return filepath.Join(home, ".ollama", "config.json"), nil
+}
+
+func legacyConfigPath() (string, error) {
 	home, err := os.UserHomeDir()
 	if err != nil {
 		return "", err
@@ -27,6 +37,55 @@ func configPath() (string, error) {
 	return filepath.Join(home, ".ollama", "config", "config.json"), nil
 }
 
+// migrateConfig moves the config from the legacy path to ~/.ollama/config.json
+func migrateConfig() (bool, error) {
+	oldPath, err := legacyConfigPath()
+	if err != nil {
+		return false, err
+	}
+
+	oldData, err := os.ReadFile(oldPath)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return false, nil
+		}
+		return false, err
+	}
+
+	var js json.RawMessage
+	if err := json.Unmarshal(oldData, &js); err != nil {
+		slog.Warn("legacy config has invalid JSON, skipping migration", "path", oldPath, "error", err)
+		return false, nil
+	}
+
+	if _, err := backupToTmp(oldPath); err != nil {
+		return false, fmt.Errorf("backup legacy config: %w", err)
+	}
+
+	newPath, err := configPath()
+	if err != nil {
+		return false, err
+	}
+
+	if err := os.MkdirAll(filepath.Dir(newPath), 0o755); err != nil {
+		return false, err
+	}
+	if err := writeWithBackup(newPath, oldData); err != nil {
+		return false, fmt.Errorf("write new config: %w", err)
+	}
+
+	written, err := os.ReadFile(newPath)
+	if err != nil || !bytes.Equal(written, oldData) {
+		return false, fmt.Errorf("verification failed after writing new config")
+	}
+
+	_ = os.Remove(oldPath)
+	_ = os.Remove(filepath.Dir(oldPath)) // clean up empty directory
+
+	slog.Info("migrated config", "from", oldPath, "to", newPath)
+	return true, nil
+}
+
 func load() (*config, error) {
 	path, err := configPath()
 	if err != nil {
@@ -34,6 +93,11 @@ func load() (*config, error) {
 	}
 
 	data, err := os.ReadFile(path)
+	if err != nil && os.IsNotExist(err) {
+		if migrated, merr := migrateConfig(); merr == nil && migrated {
+			data, err = os.ReadFile(path)
+		}
+	}
 	if err != nil {
 		if os.IsNotExist(err) {
 			return &config{Integrations: make(map[string]*integration)}, nil

cmd/config/config_test.go

@@ -200,12 +200,10 @@ func TestLoadIntegration_CorruptedJSON(t *testing.T) {
 	tmpDir := t.TempDir()
 	setTestHome(t, tmpDir)
 
-	// Create corrupted config.json file
-	dir := filepath.Join(tmpDir, ".ollama", "config")
+	dir := filepath.Join(tmpDir, ".ollama")
 	os.MkdirAll(dir, 0o755)
 	os.WriteFile(filepath.Join(dir, "config.json"), []byte(`{corrupted json`), 0o644)
 
-	// Corrupted file is treated as empty, so loadIntegration returns not found
 	_, err := loadIntegration("test")
 	if err == nil {
 		t.Error("expected error for nonexistent integration in corrupted file")
@@ -267,7 +265,7 @@ func TestConfigPath(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	expected := filepath.Join(tmpDir, ".ollama", "config", "config.json")
+	expected := filepath.Join(tmpDir, ".ollama", "config.json")
 	if path != expected {
 		t.Errorf("expected %s, got %s", expected, path)
 	}
@@ -322,6 +320,211 @@ func TestLoad(t *testing.T) {
 	})
 }
 
+func TestMigrateConfig(t *testing.T) {
+	t.Run("migrates legacy file to new location", func(t *testing.T) {
+		tmpDir := t.TempDir()
+		setTestHome(t, tmpDir)
+
+		legacyDir := filepath.Join(tmpDir, ".ollama", "config")
+		os.MkdirAll(legacyDir, 0o755)
+		data := []byte(`{"integrations":{"claude":{"models":["llama3.2"]}}}`)
+		os.WriteFile(filepath.Join(legacyDir, "config.json"), data, 0o644)
+
+		migrated, err := migrateConfig()
+		if err != nil {
+			t.Fatal(err)
+		}
+		if !migrated {
+			t.Fatal("expected migration to occur")
+		}
+
+		newPath, _ := configPath()
+		got, err := os.ReadFile(newPath)
+		if err != nil {
+			t.Fatalf("new config not found: %v", err)
+		}
+		if string(got) != string(data) {
+			t.Errorf("content mismatch: got %s", got)
+		}
+
+		if _, err := os.Stat(filepath.Join(legacyDir, "config.json")); !os.IsNotExist(err) {
+			t.Error("legacy file should have been removed")
+		}
+
+		if _, err := os.Stat(legacyDir); !os.IsNotExist(err) {
+			t.Error("legacy directory should have been removed")
+		}
+	})
+
+	t.Run("no-op when no legacy file exists", func(t *testing.T) {
+		tmpDir := t.TempDir()
+		setTestHome(t, tmpDir)
+
+		migrated, err := migrateConfig()
+		if err != nil {
+			t.Fatal(err)
+		}
+		if migrated {
+			t.Error("expected no migration")
+		}
+	})
+
+	t.Run("skips corrupt legacy file", func(t *testing.T) {
+		tmpDir := t.TempDir()
+		setTestHome(t, tmpDir)
+
+		legacyDir := filepath.Join(tmpDir, ".ollama", "config")
+		os.MkdirAll(legacyDir, 0o755)
+		os.WriteFile(filepath.Join(legacyDir, "config.json"), []byte(`{corrupt`), 0o644)
+
+		migrated, err := migrateConfig()
+		if err != nil {
+			t.Fatal(err)
+		}
+		if migrated {
+			t.Error("should not migrate corrupt file")
+		}
+
+		if _, err := os.Stat(filepath.Join(legacyDir, "config.json")); os.IsNotExist(err) {
+			t.Error("corrupt legacy file should not have been deleted")
+		}
+	})
+
+	t.Run("new path takes precedence over legacy", func(t *testing.T) {
+		tmpDir := t.TempDir()
+		setTestHome(t, tmpDir)
+
+		legacyDir := filepath.Join(tmpDir, ".ollama", "config")
+		os.MkdirAll(legacyDir, 0o755)
+		os.WriteFile(filepath.Join(legacyDir, "config.json"), []byte(`{"integrations":{"old":{"models":["old-model"]}}}`), 0o644)
+
+		newDir := filepath.Join(tmpDir, ".ollama")
+		os.WriteFile(filepath.Join(newDir, "config.json"), []byte(`{"integrations":{"new":{"models":["new-model"]}}}`), 0o644)
+
+		cfg, err := load()
+		if err != nil {
+			t.Fatal(err)
+		}
+		if _, ok := cfg.Integrations["new"]; !ok {
+			t.Error("expected new-path integration to be loaded")
+		}
+		if _, ok := cfg.Integrations["old"]; ok {
+			t.Error("legacy integration should not have been loaded")
+		}
+	})
+
+	t.Run("idempotent when called twice", func(t *testing.T) {
+		tmpDir := t.TempDir()
+		setTestHome(t, tmpDir)
+
+		legacyDir := filepath.Join(tmpDir, ".ollama", "config")
+		os.MkdirAll(legacyDir, 0o755)
+		os.WriteFile(filepath.Join(legacyDir, "config.json"), []byte(`{"integrations":{}}`), 0o644)
+
+		if _, err := migrateConfig(); err != nil {
+			t.Fatal(err)
+		}
+
+		migrated, err := migrateConfig()
+		if err != nil {
+			t.Fatal(err)
+		}
+		if migrated {
+			t.Error("second migration should be a no-op")
+		}
+	})
+
+	t.Run("legacy directory preserved if not empty", func(t *testing.T) {
+		tmpDir := t.TempDir()
+		setTestHome(t, tmpDir)
+
+		legacyDir := filepath.Join(tmpDir, ".ollama", "config")
+		os.MkdirAll(legacyDir, 0o755)
+		os.WriteFile(filepath.Join(legacyDir, "config.json"), []byte(`{"integrations":{}}`), 0o644)
+		os.WriteFile(filepath.Join(legacyDir, "other-file.txt"), []byte("keep me"), 0o644)
+
+		if _, err := migrateConfig(); err != nil {
+			t.Fatal(err)
+		}
+
+		if _, err := os.Stat(legacyDir); os.IsNotExist(err) {
+			t.Error("directory with other files should not have been removed")
+		}
+		if _, err := os.Stat(filepath.Join(legacyDir, "other-file.txt")); os.IsNotExist(err) {
+			t.Error("other files in legacy directory should be untouched")
+		}
+	})
+
+	t.Run("backup created in tmp", func(t *testing.T) {
+		tmpDir := t.TempDir()
+		setTestHome(t, tmpDir)
+
+		legacyDir := filepath.Join(tmpDir, ".ollama", "config")
+		os.MkdirAll(legacyDir, 0o755)
+		os.WriteFile(filepath.Join(legacyDir, "config.json"), []byte(`{"integrations":{}}`), 0o644)
+
+		if _, err := migrateConfig(); err != nil {
+			t.Fatal(err)
+		}
+
+		entries, err := os.ReadDir(backupDir())
+		if err != nil {
+			t.Fatal(err)
+		}
+		found := false
+		for _, e := range entries {
+			if strings.HasPrefix(e.Name(), "config.json.") {
+				found = true
+				break
+			}
+		}
+		if !found {
+			t.Error("expected backup file in tmp directory")
+		}
+	})
+
+	t.Run("save writes to new path after migration", func(t *testing.T) {
+		tmpDir := t.TempDir()
+		setTestHome(t, tmpDir)
+
+		legacyDir := filepath.Join(tmpDir, ".ollama", "config")
+		os.MkdirAll(legacyDir, 0o755)
+		os.WriteFile(filepath.Join(legacyDir, "config.json"), []byte(`{"integrations":{"claude":{"models":["llama3.2"]}}}`), 0o644)
+
+		// load triggers migration, then save should write to new path
+		if err := saveIntegration("codex", []string{"qwen2.5"}); err != nil {
+			t.Fatal(err)
+		}
+
+		newPath := filepath.Join(tmpDir, ".ollama", "config.json")
+		if _, err := os.Stat(newPath); os.IsNotExist(err) {
+			t.Error("save should write to new path")
+		}
+
+		// old path should not be recreated
+		if _, err := os.Stat(filepath.Join(legacyDir, "config.json")); !os.IsNotExist(err) {
+			t.Error("save should not recreate legacy path")
+		}
+	})
+
+	t.Run("load triggers migration transparently", func(t *testing.T) {
+		tmpDir := t.TempDir()
+		setTestHome(t, tmpDir)
+
+		legacyDir := filepath.Join(tmpDir, ".ollama", "config")
+		os.MkdirAll(legacyDir, 0o755)
+		os.WriteFile(filepath.Join(legacyDir, "config.json"), []byte(`{"integrations":{"claude":{"models":["llama3.2"]}}}`), 0o644)
+
+		cfg, err := load()
+		if err != nil {
+			t.Fatal(err)
+		}
+		if cfg.Integrations["claude"] == nil || cfg.Integrations["claude"].Models[0] != "llama3.2" {
+			t.Error("migration via load() did not preserve data")
+		}
+	})
+}
+
 func TestSave(t *testing.T) {
 	tmpDir := t.TempDir()
 	setTestHome(t, tmpDir)