feat(spec): support tool aliases (#107)

closes #57

IRIS now automatically read and suggest internal configuration aliases
for Git (`.gitconfig`, `.git/config`) and Cargo (`.cargo/config.toml`)

- Added the `Provider` interface and extended registry for CLI tools
that define aliases
- Git: parse aliases via `git config --show-scope`, supporting raw
tab/space separation and scope differentiation
- Cargo: traverse the directory tree upwards to root to read the
`.cargo/config.toml` configuration
- 0ms hot-path caching: key caching is calculated entirely via `os.Stat`
mtime (no subprocess spawn) combined with a 2-second TTL window to
ensure 0ms latency when typing
- Lookup integration: display alias suggestions at the subcommand level
and automatically expand aliases as the user enters further arguments
(ignore shell pipeline commands starting with `!`)

spec/lookup_test.go

@@ -6,6 +6,8 @@ import (
 	"strings"
 	"sync"
 	"testing"
+
+	"github.com/versenilvis/iris/spec/alias"
 )
 
 func TestLookup(t *testing.T) {
@@ -231,3 +233,160 @@ func TestLookup_NestedDirectoryTrailingSpace(t *testing.T) {
 		t.Errorf("expected hello.txt in results, got %v", results)
 	}
 }
+
+type mockGitProvider struct{}
+
+func (m *mockGitProvider) ToolName() string { return "git" }
+func (m *mockGitProvider) GetAliases(cwd string) []alias.AliasEntry {
+	return []alias.AliasEntry{
+		{
+			Name:      "co",
+			Expansion: "checkout",
+			Scope:     "global",
+		},
+		{
+			Name:      "recent",
+			Expansion: "!git for-each-ref --sort=committerdate --format='%(committerdate:relative) %(refname:short)' refs/heads/ | tail -10",
+			Scope:     "global",
+		},
+		{
+			Name:      "local-alias",
+			Expansion: "status",
+			Scope:     "local",
+		},
+	}
+}
+
+func TestLookup_GitRecentAlias(t *testing.T) {
+	ResetRegistry()
+	Register(&Spec{
+		Name: "git",
+		Subcommands: []Subcommand{
+			{Name: "commit"},
+			{Name: "checkout", Options: []Option{{Name: "-b"}}},
+		},
+	})
+	alias.Register(&mockGitProvider{})
+	t.Cleanup(alias.Reset)
+
+	// Test Type 1: Standard subcommand alias 'git co' -> 'git checkout'
+	resultsCo := Lookup("git co ")
+	foundCo := false
+	for _, r := range resultsCo {
+		if strings.Contains(r.Cmd, "-b") {
+			foundCo = true
+			break
+		}
+	}
+	if !foundCo {
+		t.Errorf("expected '-b' option after expanding 'git co ', got %v", resultsCo)
+	}
+
+	// Test Type 2: Shell pipeline alias 'git rec' -> 'git recent'
+	resultsRec := Lookup("git rec")
+	foundRec := false
+	for _, r := range resultsRec {
+		if strings.Contains(r.Cmd, "git recent") {
+			foundRec = true
+			if r.Priority != 70 {
+				t.Errorf("expected global alias priority 70, got %d", r.Priority)
+			}
+			break
+		}
+	}
+	if !foundRec {
+		t.Errorf("expected 'git recent' suggestion for 'git rec', got %v", resultsRec)
+	}
+
+	// Test Local Scope Priority (Priority = 85)
+	resultsLocal := Lookup("git local")
+	foundLocal := false
+	for _, r := range resultsLocal {
+		if strings.Contains(r.Cmd, "git local-alias") {
+			foundLocal = true
+			if r.Priority != 85 {
+				t.Errorf("expected local alias priority 85, got %d", r.Priority)
+			}
+			break
+		}
+	}
+	if !foundLocal {
+		t.Errorf("expected 'git local-alias' suggestion, got %v", resultsLocal)
+	}
+
+	// Test Type 2 expansion with trailing space: 'git recent ' (shell pipeline alias starting with !) should be skipped and return nil
+	resultsRecentSpace := Lookup("git recent ")
+	if len(resultsRecentSpace) != 0 {
+		t.Errorf("expected 0 suggestions for shell pipeline alias 'git recent ', got %v", resultsRecentSpace)
+	}
+}
+
+func TestLookup_InvalidSubcommandAfterAliasExpansion(t *testing.T) {
+	ResetRegistry()
+	Register(&Spec{
+		Name: "git",
+		Subcommands: []Subcommand{
+			{Name: "commit"},
+			{Name: "status", Subcommands: []Subcommand{{Name: "porcelain"}}},
+		},
+	})
+	alias.Register(&mockGitProvider{})
+
+	// token beyond the alias expansion must be validated against the expanded subcommand
+	results := Lookup("git local-alias badcmd ")
+	if len(results) != 0 {
+		t.Errorf("expected 0 suggestions for invalid subcommand after alias expansion, got %v", results)
+	}
+
+	// expansion itself is still allowed even when it is not a registered subcommand
+	resultsOk := Lookup("git co ")
+	if len(resultsOk) == 0 {
+		t.Errorf("expected suggestions for expanded alias 'git co ', got none")
+	}
+}
+
+func TestLookup_RealGitProvider(t *testing.T) {
+	ResetRegistry()
+	Register(&Spec{
+		Name: "git",
+	})
+	alias.Reset()
+
+	// Isolate from the developer's real git configuration by pointing HOME at a temp dir
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	if err := os.WriteFile(filepath.Join(home, ".gitconfig"), []byte("[alias]\nrecent = for-each-ref --sort=committerdate refs/heads\n"), 0644); err != nil {
+		t.Fatal(err)
+	}
+
+	cwd, _ := os.Getwd()
+	provider := &alias.GitProvider{}
+	aliases := provider.GetAliases(cwd)
+	t.Logf("Real Git aliases: %v", aliases)
+	foundAlias := false
+	for _, a := range aliases {
+		if a.Name == "recent" {
+			foundAlias = true
+			break
+		}
+	}
+	if !foundAlias {
+		t.Skipf("git unavailable or could not read isolated config, got aliases: %v", aliases)
+	}
+	alias.Register(provider)
+	t.Cleanup(alias.Reset)
+
+	results := Lookup("git rec")
+	t.Logf("Lookup('git rec') results: %v", results)
+	found := false
+	for _, r := range results {
+		if strings.Contains(r.Cmd, "recent") {
+			found = true
+			break
+		}
+	}
+	if !found {
+		t.Errorf("expected 'git recent' in results for real GitProvider, got %v", results)
+	}
+}
+