cmd/lava: add tests to "lava scan" command

cmd/lava/internal/scan/scan.go

@@ -48,6 +48,9 @@ func init() {
 	CmdScan.Run = run // Break initialization cycle.
 }
 
+// osExit is used by tests to capture the exit code.
+var osExit = os.Exit
+
 // run is the entry point of the scan command.
 func run(args []string) error {
 	if len(args) > 0 {
@@ -69,6 +72,7 @@ func run(args []string) error {
 	if err = os.Chdir(filepath.Dir(*cfgfile)); err != nil {
 		return fmt.Errorf("change directory: %w", err)
 	}
+
 	metrics.Collect("lava_version", cfg.LavaVersion)
 	metrics.Collect("targets", cfg.Targets)
 
@@ -98,7 +102,8 @@ func run(args []string) error {
 			return fmt.Errorf("write metrics: %w", err)
 		}
 	}
-	os.Exit(int(exitCode))
+
+	osExit(int(exitCode))
 
 	return nil
 }

cmd/lava/internal/scan/scan_test.go

@@ -0,0 +1,100 @@
+// Copyright 2023 Adevinta
+
+package scan
+
+import (
+	"flag"
+	"log/slog"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/jroimartin/clilog"
+
+	"github.com/adevinta/lava/internal/gitserver/gittest"
+)
+
+func TestMain(m *testing.M) {
+	flag.Parse()
+
+	level := slog.LevelError
+	if testing.Verbose() {
+		level = slog.LevelDebug
+	}
+
+	h := clilog.NewCLIHandler(os.Stderr, &clilog.HandlerOptions{Level: level})
+	slog.SetDefault(slog.New(h))
+
+	os.Exit(m.Run())
+}
+
+func TestRun(t *testing.T) {
+	tests := []struct {
+		name         string
+		wantExitCode int
+		repo         string
+	}{
+		{
+			name:         "good repo",
+			wantExitCode: 0,
+			repo:         "testdata/goodrepo.tar",
+		},
+		{
+			name:         "vulnerable repo",
+			wantExitCode: 103,
+			repo:         "testdata/vulnrepo.tar",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			oldPwd := mustGetwd()
+			oldCfgfile := *cfgfile
+			oldOsExit := osExit
+			defer func() {
+				mustChdir(oldPwd)
+				*cfgfile = oldCfgfile
+				osExit = oldOsExit
+			}()
+
+			tmpPath, err := gittest.ExtractTemp(tt.repo)
+			if err != nil {
+				t.Fatalf("unexpected error extracting test repository: %v", err)
+			}
+			defer os.RemoveAll(tmpPath)
+
+			*cfgfile = filepath.Join(tmpPath, "lava.yaml")
+
+			var exitCode int
+			osExit = func(status int) {
+				exitCode = status
+			}
+
+			if err := run(nil); err != nil {
+				t.Fatalf("run error: %v", err)
+			}
+
+			if exitCode != tt.wantExitCode {
+				t.Errorf("unexpected exit code: got: %v, want: %v", exitCode, tt.wantExitCode)
+			}
+		})
+	}
+}
+
+// mustGetwd returns a rooted path name corresponding to the current
+// directory. It panics on error.
+func mustGetwd() string {
+	wd, err := os.Getwd()
+	if err != nil {
+		panic(err)
+	}
+	return wd
+}
+
+// mustChdir changes the current working directory to the named
+// directory. It panics on error.
+func mustChdir(path string) {
+	if err := os.Chdir(path); err != nil {
+		panic(err)
+	}
+}