test(brew): add tests for parseBrewInfoVersion, parseBrewOutdated, semverCmp, parseVersionSuffix

Add comprehensive unit tests for untested brew parse functions:
- parseBrewInfoVersion: formula, cask, empty, invalid JSON, no results
- parseBrewOutdated: formulae only, casks only, mixed, empty, invalid
- semverCmp: equality, ordering, multi-digit, edge cases
- parseVersionSuffix: versioned formulae, plain names, edge cases
- Additional edge cases for parseBrewInfo, parseBrewSearch, parseBrewList

Increases brew package test coverage from 14.4% to 26.7%.

brew/brew_test.go

@@ -206,6 +206,227 @@ func TestCapabilities(t *testing.T) {
 	}
 }
 
+func TestParseBrewInfoVersion(t *testing.T) {
+	t.Run("formula", func(t *testing.T) {
+		input := `{"formulae":[{"name":"git","full_name":"git","desc":"Distributed revision control system","versions":{"stable":"2.43.0"},"installed":[]}],"casks":[]}`
+		ver := parseBrewInfoVersion(input)
+		if ver != "2.43.0" {
+			t.Errorf("expected '2.43.0', got %q", ver)
+		}
+	})
+
+	t.Run("cask", func(t *testing.T) {
+		input := `{"formulae":[],"casks":[{"token":"visual-studio-code","name":["Visual Studio Code"],"desc":"Open-source code editor","version":"1.85.0"}]}`
+		ver := parseBrewInfoVersion(input)
+		if ver != "1.85.0" {
+			t.Errorf("expected '1.85.0', got %q", ver)
+		}
+	})
+
+	t.Run("empty", func(t *testing.T) {
+		ver := parseBrewInfoVersion("")
+		if ver != "" {
+			t.Errorf("expected empty, got %q", ver)
+		}
+	})
+
+	t.Run("invalid json", func(t *testing.T) {
+		ver := parseBrewInfoVersion("not json")
+		if ver != "" {
+			t.Errorf("expected empty, got %q", ver)
+		}
+	})
+
+	t.Run("no formulae or casks", func(t *testing.T) {
+		input := `{"formulae":[],"casks":[]}`
+		ver := parseBrewInfoVersion(input)
+		if ver != "" {
+			t.Errorf("expected empty, got %q", ver)
+		}
+	})
+}
+
+func TestParseBrewOutdated(t *testing.T) {
+	t.Run("formulae only", func(t *testing.T) {
+		input := `{"formulae":[{"name":"git","installed_versions":["2.43.0"],"current_version":"2.44.0"},{"name":"go","installed_versions":["1.21.6"],"current_version":"1.22.0"}],"casks":[]}`
+		pkgs := parseBrewOutdated(input)
+		if len(pkgs) != 2 {
+			t.Fatalf("expected 2 packages, got %d", len(pkgs))
+		}
+		if pkgs[0].Name != "git" || pkgs[0].Version != "2.44.0" {
+			t.Errorf("unexpected first package: %+v", pkgs[0])
+		}
+		if !pkgs[0].Installed {
+			t.Error("expected Installed=true")
+		}
+	})
+
+	t.Run("casks only", func(t *testing.T) {
+		input := `{"formulae":[],"casks":[{"name":"firefox","installed_versions":"119.0","current_version":"120.0"}]}`
+		pkgs := parseBrewOutdated(input)
+		if len(pkgs) != 1 {
+			t.Fatalf("expected 1 package, got %d", len(pkgs))
+		}
+		if pkgs[0].Name != "firefox" || pkgs[0].Version != "120.0" {
+			t.Errorf("unexpected package: %+v", pkgs[0])
+		}
+	})
+
+	t.Run("mixed", func(t *testing.T) {
+		input := `{"formulae":[{"name":"git","installed_versions":["2.43.0"],"current_version":"2.44.0"}],"casks":[{"name":"firefox","installed_versions":"119.0","current_version":"120.0"}]}`
+		pkgs := parseBrewOutdated(input)
+		if len(pkgs) != 2 {
+			t.Fatalf("expected 2 packages, got %d", len(pkgs))
+		}
+	})
+
+	t.Run("empty", func(t *testing.T) {
+		pkgs := parseBrewOutdated("")
+		if len(pkgs) != 0 {
+			t.Errorf("expected 0 packages, got %d", len(pkgs))
+		}
+	})
+
+	t.Run("no outdated", func(t *testing.T) {
+		input := `{"formulae":[],"casks":[]}`
+		pkgs := parseBrewOutdated(input)
+		if len(pkgs) != 0 {
+			t.Errorf("expected 0 packages, got %d", len(pkgs))
+		}
+	})
+
+	t.Run("invalid json", func(t *testing.T) {
+		pkgs := parseBrewOutdated("not json")
+		if len(pkgs) != 0 {
+			t.Errorf("expected 0 packages, got %d", len(pkgs))
+		}
+	})
+}
+
+func TestSemverCmp(t *testing.T) {
+	tests := []struct {
+		name string
+		a, b string
+		want int
+	}{
+		{"equal", "1.0.0", "1.0.0", 0},
+		{"less major", "1.0.0", "2.0.0", -1},
+		{"greater major", "2.0.0", "1.0.0", 1},
+		{"less minor", "1.2.3", "1.3.0", -1},
+		{"less patch", "1.2.3", "1.2.4", -1},
+		{"multi-digit", "1.10.0", "1.9.0", 1},
+		{"short vs long equal", "1.0", "1.0.0", 0},
+		{"short vs long less", "1.0", "1.0.1", -1},
+		{"short vs long greater", "1.1", "1.0.9", 1},
+		{"single component", "5", "3", 1},
+		{"single equal", "3", "3", 0},
+		{"empty vs empty", "", "", 0},
+		{"empty vs version", "", "1.0", -1},
+		{"version vs empty", "1.0", "", 1},
+		{"four components", "1.2.3.4", "1.2.3.5", -1},
+		{"different lengths", "1.0.0.0", "1.0.0", 0},
+		{"real brew versions", "2.43.0", "2.44.0", -1},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := semverCmp(tt.a, tt.b)
+			if got != tt.want {
+				t.Errorf("semverCmp(%q, %q) = %d, want %d", tt.a, tt.b, got, tt.want)
+			}
+		})
+	}
+}
+
+func TestParseVersionSuffix(t *testing.T) {
+	tests := []struct {
+		input       string
+		wantName    string
+		wantVersion string
+	}{
+		{"python@3.12", "python", "3.12"},
+		{"node@18", "node", "18"},
+		{"git", "git", ""},
+		{"ruby@3.2", "ruby", "3.2"},
+		{"", "", ""},
+		{"@3.12", "@3.12", ""}, // @ at position 0, LastIndex returns 0 which is not > 0
+	}
+	for _, tt := range tests {
+		t.Run(tt.input, func(t *testing.T) {
+			gotName, gotVer := parseVersionSuffix(tt.input)
+			if gotName != tt.wantName || gotVer != tt.wantVersion {
+				t.Errorf("parseVersionSuffix(%q) = (%q, %q), want (%q, %q)",
+					tt.input, gotName, gotVer, tt.wantName, tt.wantVersion)
+			}
+		})
+	}
+}
+
+func TestParseBrewInfo_Empty(t *testing.T) {
+	pkg := parseBrewInfo("")
+	if pkg != nil {
+		t.Error("expected nil for empty input")
+	}
+}
+
+func TestParseBrewInfo_InvalidJSON(t *testing.T) {
+	pkg := parseBrewInfo("not json")
+	if pkg != nil {
+		t.Error("expected nil for invalid JSON")
+	}
+}
+
+func TestParseBrewInfo_NoFormulaeOrCasks(t *testing.T) {
+	input := `{"formulae":[],"casks":[]}`
+	pkg := parseBrewInfo(input)
+	if pkg != nil {
+		t.Error("expected nil when no formulae or casks")
+	}
+}
+
+func TestParseBrewSearch_HeadersOnly(t *testing.T) {
+	input := `==> Formulae
+
+==> Casks
+`
+	pkgs := parseBrewSearch(input)
+	if len(pkgs) != 0 {
+		t.Errorf("expected 0 packages, got %d", len(pkgs))
+	}
+}
+
+func TestParseBrewSearch_MultiplePerLine(t *testing.T) {
+	input := "git  go  vim  curl\n"
+	pkgs := parseBrewSearch(input)
+	if len(pkgs) != 4 {
+		t.Fatalf("expected 4 packages, got %d", len(pkgs))
+	}
+	names := []string{"git", "go", "vim", "curl"}
+	for i, want := range names {
+		if pkgs[i].Name != want {
+			t.Errorf("pkg[%d].Name = %q, want %q", i, pkgs[i].Name, want)
+		}
+	}
+}
+
+func TestParseBrewList_NameOnly(t *testing.T) {
+	input := "git\ncurl\n"
+	pkgs := parseBrewList(input)
+	if len(pkgs) != 2 {
+		t.Fatalf("expected 2 packages, got %d", len(pkgs))
+	}
+	if pkgs[0].Version != "" {
+		t.Errorf("expected empty version, got %q", pkgs[0].Version)
+	}
+}
+
+func TestParseBrewList_WhitespaceLines(t *testing.T) {
+	input := "  \n\n  git 2.43.0\n  \n"
+	pkgs := parseBrewList(input)
+	if len(pkgs) != 1 {
+		t.Fatalf("expected 1 package, got %d", len(pkgs))
+	}
+}
+
 func TestInterfaceNonCompliance(t *testing.T) {
 	var m snack.Manager = New()
 	if _, ok := m.(snack.Holder); ok {