Test that what is well-formed and means one thing loads: ignored parts, constant samples, any JSON value, weight 0, an unread name, a stray rows file, a tagless struct and flags with no effect

internal/datafiles/datafiles_test.go

@@ -80,10 +80,9 @@ func TestReadRowsReadsOnlyAFileBesideTheCategory(t *testing.T) {
 	}
 }
 
-func TestWalkRefusesARowsFileNoCategoryNames(t *testing.T) {
-	_, err := walk(t, Source{fsys: fstest.MapFS{"a.json": {Data: []byte(`"x"`)}, "a.tsv": {Data: []byte("key\n")}}, label: "lbl"})
-	if err == nil || !strings.HasPrefix(err.Error(), "lbl/a.tsv: no category names it in its rows") {
-		t.Errorf("Walk = %v, want a.tsv refused as named by no category", err)
+func TestWalkIgnoresARowsFileNoCategoryNames(t *testing.T) {
+	if _, err := walk(t, Source{fsys: fstest.MapFS{"a.json": {Data: []byte(`"x"`)}, "a.tsv": {Data: []byte("key\n")}}, label: "lbl"}); err != nil {
+		t.Errorf("Walk = %v, want a.tsv ignored", err)
 	}
 }
 

internal/rows/rows_test.go

@@ -37,7 +37,8 @@ func TestParseRefuses(t *testing.T) {
 		{"no rows", "a\n", Options{}, "has no rows below its header"},
 		{"a short row", "a\tb\n1\t2\n3\n", Options{}, "line 3 has fewer cells"},
 		{"a repeated key", "k\nx\nx\n", Options{Key: "k"}, `key "x" repeats line 2`},
-		{"a weight of zero", "k\tw\nx\t1\ny\t0\n", Options{Weight: "w"}, `weight "0" is not a positive number`},
+		{"every weight zero", "k\tw\nx\t0\ny\t0\n", Options{Weight: "w"}, "every weight is 0"},
+		{"a negative weight", "k\tw\nx\t1\ny\t-1\n", Options{Weight: "w"}, `weight "-1" is not a number of 0 or more`},
 		{"a key a selector cannot spell", "k\nx\ny|z\n", Options{Key: "k"}, `contains "|"`},
 		{"an option naming no column", "k\nx\ny\n", Options{Key: "nope"}, `key names no column "nope"`},
 	} {