Handle nil timestamps in query parameters. (#389)

We represent timestamps as `*time.Time`. However, when a nullable
timestamp is serialized to query parameters in paths.go, we panic on the
nil pointer. This patch adds a helper to wrap time formatting to safely
check and omit nil timestamps.

Note: I think we shouldn't represent all timestamps, including
non-nullable timestamps, as `*time.Time`, but I'll think about that in
another patch.

Author: jmcarp

internal/generate/paths.go

@@ -426,10 +426,7 @@ func buildPathOrQueryParams(
 			case "*int":
 				pathParams = append(pathParams, fmt.Sprintf("%q: PointerIntToStr(%s),", name, n))
 			case "*time.Time":
-				pathParams = append(
-					pathParams,
-					fmt.Sprintf("%q: %s.Format(time.RFC3339),", name, n),
-				)
+				pathParams = append(pathParams, fmt.Sprintf("%q: PointerTimeToStr(%s),", name, n))
 			default:
 				if p.Schema.Value != nil && p.Schema.Value.Type.Is("integer") {
 					pathParams = append(pathParams, fmt.Sprintf("%q: fmt.Sprint(%s),", name, n))

oxide/paths.go

@@ -7,6 +7,7 @@ import (
 	"strconv"
 	"strings"
 	"text/template"
+	"time"
 )
 
 // NewPointer returns a pointer to a given value.
@@ -24,6 +25,16 @@ func PointerIntToStr(i *int) string {
 	return strconv.Itoa(*i)
 }
 
+// PointerTimeToStr converts a *time.Time into an RFC3339 string.
+// If nil, an empty string is returned.
+func PointerTimeToStr(t *time.Time) string {
+	if t == nil {
+		return ""
+	}
+
+	return t.Format(time.RFC3339)
+}
+
 // resolveRelative combines a url base with a relative path.
 func resolveRelative(basestr, relstr string) string {
 	u, _ := url.Parse(basestr)