feat(telemetry): record backing-binary versions on spans, captured at build time

pkg/gotenberg/buildversions_test.go

@@ -0,0 +1,81 @@
+package gotenberg
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestBuildVersion(t *testing.T) {
+	for _, tc := range []struct {
+		scenario  string
+		fileBody  string
+		writeFile bool
+		setEnv    bool
+		moduleID  string
+		wantValue string
+		wantOk    bool
+	}{
+		{
+			scenario:  "version present",
+			fileBody:  "Chromium 146.0",
+			writeFile: true,
+			setEnv:    true,
+			moduleID:  "chromium",
+			wantValue: "Chromium 146.0",
+			wantOk:    true,
+		},
+		{
+			scenario:  "value trimmed",
+			fileBody:  "  qpdf version 11.9.0  \n",
+			writeFile: true,
+			setEnv:    true,
+			moduleID:  "qpdf",
+			wantValue: "qpdf version 11.9.0",
+			wantOk:    true,
+		},
+		{
+			scenario:  "empty file falls back",
+			fileBody:  "   \n",
+			writeFile: true,
+			setEnv:    true,
+			moduleID:  "pdftk",
+			wantValue: "",
+			wantOk:    false,
+		},
+		{
+			scenario:  "missing file falls back",
+			writeFile: false,
+			setEnv:    true,
+			moduleID:  "exiftool",
+			wantValue: "",
+			wantOk:    false,
+		},
+		{
+			scenario:  "env unset falls back",
+			setEnv:    false,
+			moduleID:  "chromium",
+			wantValue: "",
+			wantOk:    false,
+		},
+	} {
+		t.Run(tc.scenario, func(t *testing.T) {
+			if tc.setEnv {
+				dir := t.TempDir()
+				if tc.writeFile {
+					if err := os.WriteFile(filepath.Join(dir, tc.moduleID), []byte(tc.fileBody), 0o600); err != nil {
+						t.Fatalf("write version file: %v", err)
+					}
+				}
+				t.Setenv(BuildVersionsDirPathEnvVar, dir)
+			} else {
+				t.Setenv(BuildVersionsDirPathEnvVar, "")
+			}
+
+			value, ok := BuildVersion(tc.moduleID)
+			if value != tc.wantValue || ok != tc.wantOk {
+				t.Errorf("BuildVersion(%q) = (%q, %t), want (%q, %t)", tc.moduleID, value, ok, tc.wantValue, tc.wantOk)
+			}
+		})
+	}
+}