do not assert on text output; check for crashes in all files; fix one…

… more NPE

go/cli/mcap/cmd/info.go

@@ -138,14 +138,14 @@ func printInfo(w io.Writer, info *mcap.Info) error {
 	for _, chanID := range chanIDs {
 		channel := info.Channels[chanID]
 		schema := info.Schemas[channel.SchemaID]
-		channelMessageCount := info.Statistics.ChannelMessageCounts[chanID]
-		frequency := 1e9 * float64(channelMessageCount) / float64(end-start)
 		width := digits(uint64(chanID)) + 2
 		padding := strings.Repeat(" ", maxChanIDWidth-width)
 		row := []string{
 			fmt.Sprintf("\t(%d)%s%s", channel.ID, padding, channel.Topic),
 		}
 		if info.Statistics != nil {
+			channelMessageCount := info.Statistics.ChannelMessageCounts[chanID]
+			frequency := 1e9 * float64(channelMessageCount) / float64(end-start)
 			row = append(row, fmt.Sprintf("%*d msgs (%.2f Hz)", maxCountWidth, channelMessageCount, frequency))
 		}
 		switch {

go/cli/mcap/cmd/info_test.go

@@ -3,6 +3,7 @@ package cmd
 import (
 	"bytes"
 	"os"
+	"path/filepath"
 	"strings"
 	"testing"
 
@@ -11,84 +12,30 @@ import (
 )
 
 func TestInfo(t *testing.T) {
-	cases := []struct {
-		assertion string
-		inputfile string
-		expected  string
-	}{
-		{
-			"OneMessage",
-			"../../../../tests/conformance/data/OneMessage/OneMessage-ch-chx-mx-pad-rch-rsh-st-sum.mcap",
-			`library:
-profile:
-messages:  1
-duration:  0s
-start:     0.000000002
-end:       0.000000002
-compression:
-	: [1/1 chunks] [115.00 B/115.00 B (0.00%)]
-channels:
-	(1) example  1 msgs (+Inf Hz)   : Example [c]
-attachments: 0
-metadata: 0`,
-		},
-		{
-			"OneSchemalessMessage",
-			"../../../../tests/conformance/data/OneSchemalessMessage/OneSchemalessMessage-ch-chx-mx-pad-rch-st.mcap",
-			`library:
-profile:
-messages:  1
-duration:  0s
-start:     0.000000002
-end:       0.000000002
-compression:
-	: [1/1 chunks] [70.00 B/70.00 B (0.00%)]
-channels:
-	(1) example  1 msgs (+Inf Hz)   : <no schema>
-attachments: 0
-metadata: 0`,
-		},
-		{
-			"OneSchemalessMessage_NoChannels",
-			"../../../../tests/conformance/data/OneSchemalessMessage/OneSchemalessMessage.mcap",
-			`library:
-profile:
-channels:
-attachments: unknown
-metadata: unknown`,
-		},
-	}
-	for _, c := range cases {
-		input, err := os.ReadFile(c.inputfile)
-		assert.Nil(t, err)
-		r := bytes.NewReader(input)
-		w := new(bytes.Buffer)
-
-		t.Run(c.assertion, func(t *testing.T) {
-			reader, err := mcap.NewReader(r)
-			assert.Nil(t, err)
-			defer reader.Close()
-			info, err := reader.Info()
-			assert.Nil(t, err)
-			err = printInfo(w, info)
-			assert.Nil(t, err)
-
-			// for each line, strip leading/trailing whitespace
-			// this prevents test failures from formatting changes
-			actualLines := strings.Split(strings.TrimSpace(w.String()), "\n")
-			expectedLines := strings.Split(strings.TrimSpace(c.expected), "\n")
-
-			for i, line := range actualLines {
-				actualLines[i] = strings.TrimSpace(line)
-			}
-			for i, line := range expectedLines {
-				expectedLines[i] = strings.TrimSpace(line)
-			}
-
-			actualStripped := strings.Join(actualLines, "\n")
-			expectedStripped := strings.Join(expectedLines, "\n")
-
-			assert.Equal(t, expectedStripped, actualStripped)
-		})
-	}
+	err := filepath.Walk("../../../../tests/conformance/data/", func(path string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+		if info.IsDir() {
+			return nil
+		}
+		if strings.HasSuffix(path, ".mcap") {
+			t.Run(path, func(t *testing.T) {
+				input, err := os.ReadFile(path)
+				assert.Nil(t, err)
+				r := bytes.NewReader(input)
+				w := new(bytes.Buffer)
+
+				reader, err := mcap.NewReader(r)
+				assert.Nil(t, err)
+				defer reader.Close()
+				info, err := reader.Info()
+				assert.Nil(t, err)
+				err = printInfo(w, info)
+				assert.Nil(t, err)
+			})
+		}
+		return nil
+	})
+	assert.Nil(t, err)
 }