fixup! lottie: add convert function

Signed-off-by: Sumner Evans <[email protected]>

lottie/convert.go

@@ -49,22 +49,21 @@ func SetPath(path string) {
 //
 // The outputFilename and outputWriter parameters are mutually exclusive.
 func Convert(ctx context.Context, input io.Reader, outputFilename string, outputWriter io.Writer, format string, width, height int, extraArgs ...string) error {
-	// Verify the input parameters and calculate the actual filenames that will
-	// be used when shelling out to lottieconverter.
+	// Verify the input parameters and calculate the actual outputFilename that
+	// will be used when shelling out to lottieconverter.
 	//
 	// We are panicking here because it's a programming error to call this
 	// function with invalid parameters.
-	out := outputFilename
 	if outputFilename == "" && outputWriter == nil {
 		panic("lottie.Convert: either outputFile or outputWriter must be provided")
 	} else if outputWriter != nil {
 		if outputFilename != "" {
 			panic("lottie.Convert: only one of outputFile or outputWriter can be provided")
 		}
-		out = "-"
+		outputFilename = "-"
 	}
 
-	args := []string{"-", out, format, fmt.Sprintf("%dx%d", width, height)}
+	args := []string{"-", outputFilename, format, fmt.Sprintf("%dx%d", width, height)}
 	args = append(args, extraArgs...)
 
 	cmd := exec.CommandContext(ctx, lottieconverterPath, args...)