clairctl: fix and codify import arguments

This fixes a case where `./file` was getting interpreted as a URI, and
adds a test to codify the behavior.

Signed-off-by: Hank Donnay <[email protected]>

cmd/clairctl/import.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"context"
 	"errors"
 	"fmt"
 	"io"
@@ -46,34 +47,11 @@ func importAction(c *cli.Context) error {
 	}
 	inName := args.First()
 
-	var in io.Reader
-	u, uerr := url.Parse(inName)
-	f, ferr := os.Open(inName)
-	if f != nil {
-		defer f.Close()
-	}
-	switch {
-	case uerr == nil:
-		req, err := http.NewRequestWithContext(ctx, http.MethodGet, u.String(), nil)
-		if err != nil {
-			return err
-		}
-		res, err := cl.Do(req)
-		if res != nil {
-			defer res.Body.Close()
-		}
-		if err != nil {
-			return err
-		}
-		if res.StatusCode != http.StatusOK {
-			return fmt.Errorf("unexpected response: %d %s", res.StatusCode, res.Status)
-		}
-		in = res.Body
-	case ferr == nil:
-		in = f
-	default:
-		return fmt.Errorf("unable to make sense of argument %q", inName)
+	in, err := openInput(ctx, cl, inName)
+	if err != nil {
+		return err
 	}
+	defer in.Close()
 
 	pool, err := pgxpool.Connect(ctx, cfg.Matcher.ConnString)
 	if err != nil {
@@ -86,3 +64,30 @@ func importAction(c *cli.Context) error {
 	}
 	return nil
 }
+
+func openInput(ctx context.Context, c *http.Client, n string) (io.ReadCloser, error) {
+	f, ferr := os.Open(n)
+	if ferr == nil {
+		return f, nil
+	}
+	u, uerr := url.Parse(n)
+	if uerr == nil {
+		req, err := http.NewRequestWithContext(ctx, http.MethodGet, u.String(), nil)
+		if err != nil {
+			return nil, err
+		}
+		res, err := c.Do(req)
+		if err != nil {
+			if res != nil {
+				res.Body.Close()
+			}
+			return nil, err
+		}
+		if res.StatusCode != http.StatusOK {
+			res.Body.Close()
+			return nil, fmt.Errorf("unexpected response: %d %s", res.StatusCode, res.Status)
+		}
+		return res.Body, nil
+	}
+	return nil, fmt.Errorf("error opening input:\n\t%v\n\t%v", ferr, uerr)
+}

cmd/clairctl/import_test.go

@@ -0,0 +1,76 @@
+package main
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"reflect"
+	"testing"
+)
+
+// TestImportArg checks that the import subcommand's magic URL handling is
+// correct.
+func TestImportArg(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusOK)
+		fmt.Fprint(w, "http")
+	}))
+	defer srv.Close()
+
+	tt := []struct {
+		In  string
+		Err bool
+		Ok  func(*testing.T, io.ReadCloser)
+	}{
+		{
+			In: "import_test.go",
+			Ok: func(t *testing.T, in io.ReadCloser) {
+				if got, want := reflect.TypeOf(in), reflect.TypeOf(&os.File{}); got != want {
+					t.Errorf("got: %T, want: %T", got, want)
+				}
+			},
+		},
+		{
+			In: "./import_test.go",
+			Ok: func(t *testing.T, in io.ReadCloser) {
+				if got, want := reflect.TypeOf(in), reflect.TypeOf(&os.File{}); got != want {
+					t.Errorf("got: %T, want: %T", got, want)
+				}
+			},
+		},
+		{
+			In: srv.URL,
+			Ok: func(t *testing.T, rc io.ReadCloser) {
+				b := bytes.Buffer{}
+				if _, err := b.ReadFrom(rc); err != nil {
+					t.Errorf("read error: %v", err)
+				}
+				if got, want := b.String(), "http"; got != want {
+					t.Errorf("got: %q, want: %q", got, want)
+				}
+			},
+		},
+		{
+			In:  "invalid",
+			Err: true,
+			Ok:  func(*testing.T, io.ReadCloser) {},
+		},
+	}
+
+	ctx := context.Background()
+	for _, tc := range tt {
+		rc, err := openInput(ctx, srv.Client(), tc.In)
+		t.Logf("%q: %T; %v", tc.In, rc, err)
+		if (err != nil) && !tc.Err {
+			t.Error()
+		}
+		tc.Ok(t, rc)
+		if rc != nil {
+			rc.Close()
+		}
+	}
+}