test io.Reader failure

Author: creativeprojects

bogusreader_test.go

@@ -0,0 +1,15 @@
+package selfupdate
+
+import (
+	"errors"
+	"io"
+)
+
+type bogusReader struct{}
+
+func (r *bogusReader) Read(p []byte) (n int, err error) {
+	return 0, errors.New("cannot read")
+}
+
+// Verify interface
+var _ io.Reader = &bogusReader{}

decompress.go

@@ -40,7 +40,6 @@ var (
 // These wrapped errors can be returned:
 //  - ErrCannotDecompressFile
 //  - ErrExecutableNotFoundInArchive
-//  - ErrCannotReadStream
 func DecompressCommand(src io.Reader, url, cmd, os, arch string) (io.Reader, error) {
 	for _, fileType := range fileTypes {
 		if strings.HasSuffix(url, fileType.ext) {
@@ -58,7 +57,7 @@ func unzip(src io.Reader, cmd, os, arch string) (io.Reader, error) {
 	// So we need to read the HTTP response into a buffer at first.
 	buf, err := ioutil.ReadAll(src)
 	if err != nil {
-		return nil, fmt.Errorf("%w for zip file: %v", ErrCannotReadStream, err)
+		return nil, fmt.Errorf("%w zip file: %v", ErrCannotDecompressFile, err)
 	}
 
 	r := bytes.NewReader(buf)
@@ -111,7 +110,7 @@ func untarxz(src io.Reader, cmd, os, arch string) (io.Reader, error) {
 
 	xzip, err := xz.NewReader(src)
 	if err != nil {
-		return nil, fmt.Errorf("%w .tar.xz file: %s", ErrCannotDecompressFile, err)
+		return nil, fmt.Errorf("%w tar.xz file: %s", ErrCannotDecompressFile, err)
 	}
 
 	return unarchiveTar(xzip, cmd, os, arch)

decompress_test.go

@@ -78,7 +78,7 @@ func TestDecompressInvalidArchive(t *testing.T) {
 		{"testdata/invalid-gzip.tar.gz", "failed to decompress tar.gz file"},
 		{"testdata/invalid.xz", "failed to decompress xzip file"},
 		{"testdata/invalid-tar.tar.xz", "failed to decompress tar file"},
-		{"testdata/invalid-xz.tar.xz", "failed to decompress .tar.xz file"},
+		{"testdata/invalid-xz.tar.xz", "failed to decompress tar.xz file"},
 	} {
 		f, err := os.Open(a.name)
 		require.NoError(t, err)
@@ -142,3 +142,31 @@ func TestMatchExecutableName(t *testing.T) {
 		})
 	}
 }
+
+func TestErrorFromReader(t *testing.T) {
+	extensions := []string{
+		"zip",
+		"tar.gz",
+		"tgz",
+		"gzip",
+		"gz",
+		"tar.xz",
+		"xz",
+		"bz2",
+	}
+
+	for _, extension := range extensions {
+		t.Run(extension, func(t *testing.T) {
+			reader, err := DecompressCommand(&bogusReader{}, "foo."+extension, "foo."+extension, runtime.GOOS, runtime.GOARCH)
+			if err != nil {
+				t.Log(err)
+				assert.True(t, errors.Is(err, ErrCannotDecompressFile))
+			} else {
+				// bz2 does not return an error straight away: it only fails when you start reading from the output reader
+				_, err = ioutil.ReadAll(reader)
+				t.Log(err)
+				assert.Error(t, err)
+			}
+		})
+	}
+}

errors.go

@@ -15,5 +15,4 @@ var (
 	ErrInvalidECDSASignature       = errors.New("invalid ECDSA signature")
 	ErrCannotDecompressFile        = errors.New("failed to decompress")
 	ErrExecutableNotFoundInArchive = errors.New("executable not found")
-	ErrCannotReadStream            = errors.New("error reading from stream")
 )