engine refactor

internal/datasets/grib/idx_test.go

@@ -0,0 +1,70 @@
+package grib
+
+import "testing"
+
+const sampleIdx = `1:0:d=2024010100:HGT:1000 mb:0 hour fcst:
+2:289012:d=2024010100:HGT:975 mb:0 hour fcst:
+3:541876:d=2024010100:TMP:1000 mb:0 hour fcst:
+4:789012:d=2024010100:UGRD:1000 mb:0 hour fcst:
+5:1045678:d=2024010100:VGRD:1000 mb:0 hour fcst:
+6:1298765:d=2024010100:UGRD:975 mb:0 hour fcst:
+7:1567890:d=2024010100:UGRD:2 m above ground:0 hour fcst:
+8:1812345:d=2024010100:VGRD:975 mb:0 hour fcst:
+9:2098765:d=2024010100:HGT:500 mb:3 hour fcst:
+`
+
+func TestParseIdx(t *testing.T) {
+	entries := ParseIdx([]byte(sampleIdx))
+	if len(entries) != 9 {
+		t.Fatalf("expected 9 entries, got %d", len(entries))
+	}
+	if e := entries[0]; e.Index != 1 || e.Offset != 0 || e.Variable != "HGT" || e.LevelMB != 1000 || e.Hour != 0 || e.EndOffset != 289012 {
+		t.Errorf("entry 0: %+v", e)
+	}
+	if e := entries[6]; e.LevelMB != 0 {
+		t.Errorf("non-pressure level should have LevelMB=0, got %d", e.LevelMB)
+	}
+	if e := entries[len(entries)-1]; e.EndOffset != -1 {
+		t.Errorf("last entry EndOffset: got %d, want -1", e.EndOffset)
+	}
+}
+
+func TestFilterIdx(t *testing.T) {
+	entries := ParseIdx([]byte(sampleIdx))
+	want := map[string]bool{"HGT": true, "UGRD": true, "VGRD": true}
+	filtered := FilterIdx(entries, want)
+	// HGT@1000, HGT@975, UGRD@1000, VGRD@1000, UGRD@975, VGRD@975 = 6
+	// HGT@500 at 3hr is last entry (no EndOffset), so dropped.
+	if len(filtered) != 6 {
+		t.Errorf("expected 6, got %d", len(filtered))
+	}
+}
+
+func TestParseLevelMB(t *testing.T) {
+	cases := []struct {
+		in   string
+		want int
+	}{
+		{"1000 mb", 1000}, {"975 mb", 975}, {"1 mb", 1},
+		{"2 m above ground", 0}, {"surface", 0}, {"tropopause", 0},
+	}
+	for _, c := range cases {
+		if got := parseLevelMB(c.in); got != c.want {
+			t.Errorf("parseLevelMB(%q) = %d, want %d", c.in, got, c.want)
+		}
+	}
+}
+
+func TestParseHour(t *testing.T) {
+	cases := []struct {
+		in   string
+		want int
+	}{
+		{"0 hour fcst", 0}, {"3 hour fcst", 3}, {"192 hour fcst", 192}, {"anl", 0},
+	}
+	for _, c := range cases {
+		if got := parseHour(c.in); got != c.want {
+			t.Errorf("parseHour(%q) = %d, want %d", c.in, got, c.want)
+		}
+	}
+}