Add option to fail on empty results (#41)

Co-authored-by: Norman Gehrsitz <[email protected]>

config.go

@@ -7,23 +7,25 @@ import (
 )
 
 type config struct {
-	onlyDegression bool
-	threshold      float64
-	base           string
-	compare        []string
-	benchCmd       string
-	benchArgs      []string
-	gitPath        string
+	onlyDegression     bool
+	failWithoutResults bool
+	threshold          float64
+	base               string
+	compare            []string
+	benchCmd           string
+	benchArgs          []string
+	gitPath            string
 }
 
 func newConfig(c *cli.Context) config {
 	return config{
-		onlyDegression: c.Bool("only-degression"),
-		threshold:      c.Float64("threshold"),
-		base:           c.String("base"),
-		compare:        strings.Split(c.String("compare"), ","),
-		benchCmd:       c.String("bench-cmd"),
-		benchArgs:      strings.Fields(c.String("bench-args")),
-		gitPath:        c.String("git-path"),
+		onlyDegression:     c.Bool("only-degression"),
+		failWithoutResults: c.Bool("fail-without-results"),
+		threshold:          c.Float64("threshold"),
+		base:               c.String("base"),
+		compare:            strings.Split(c.String("compare"), ","),
+		benchCmd:           c.String("bench-cmd"),
+		benchArgs:          strings.Fields(c.String("bench-args")),
+		gitPath:            c.String("git-path"),
 	}
 }

main.go

@@ -41,6 +41,10 @@ func main() {
 				Name:  "only-degression",
 				Usage: "Show only benchmarks with worse score",
 			},
+			&cli.BoolFlag{
+				Name:  "fail-without-results",
+				Usage: "Exit with an error if the parsing fails",
+			},
 			&cli.Float64Flag{
 				Name:  "threshold",
 				Usage: "The program fails if the benchmark gets worse than the threshold",
@@ -146,6 +150,15 @@ func run(c config) error {
 		return xerrors.Errorf("failed to run a benchmark: %w", err)
 	}
 
+	if c.failWithoutResults {
+		if len(prevSet) == 0 {
+			return xerrors.New("could not parse any benchmark results for the previous commit")
+		}
+		if len(headSet) == 0 {
+			return xerrors.New("could not parse any benchmark results for the current commit")
+		}
+	}
+
 	var ratios []result
 	var rows [][]string
 	for benchName, headBenchmarks := range headSet {