Tests: a struct column need not agree on a datatype, text beside a typed column read names its text spelling, a column read is reported before its reader, and column reads through a dot, a choice and an always-null column

datatype_test.go

@@ -49,6 +49,7 @@ func TestDatatypeRejectsAValueItsTypeRejects(t *testing.T) {
 		{"items of two datatypes", `[{"format":"1","datatype":"integer"},{"format":"true","datatype":"boolean"}]`, "a column holds one datatype"},
 		{"an item beside a typed column it reads", `["{/src.score}","x"]`, `write it as {"format":"x","datatype":"integer"}`},
 		{"a typed item beside a string column it reads", `["{/src.code}",{"format":"1","datatype":"integer"}]`, `write it as {"format":"{/src.code}","datatype":"integer"}`},
+		{"text beside a typed column it reads", `["{/src.score}","n/a"]`, `to read that column as text, write {"format":"{text}","text":"{/src.score}"}`},
 		{"a datatype over a typed column", `{"format":"{/src.score}","datatype":"integer"}`, `{/src.score} takes datatype integer from the column it reads; drop "datatype"`},
 		{"another datatype over a typed column", `{"format":"{/src.score}","datatype":"number"}`, `{/src.score} takes datatype integer from the column it reads; drop "datatype"`},
 		{"a value of the column it reads", `{"format":"{/src.code}","datatype":"integer"}`, `"2x" is not an integer`},
@@ -98,6 +99,13 @@ func TestDatatypeRejectsAValueItsTypeRejects(t *testing.T) {
 			t.Errorf("%s: NewTemplate = %v, want the inline template refused the same way", c.name, err)
 		}
 	}
+	_, err := New(WithoutShippedData(), WithDataPath(writeData(t, map[string]string{
+		"a": `{"format":"","c":["{/b.x}",{"format":"1","datatype":"integer"}]}`,
+		"b": `{"format":"","x":["2",{"format":"1","datatype":"integer"}]}`,
+	})))
+	if want := `b: field "x": item "2"`; err == nil || !strings.Contains(err.Error(), want) {
+		t.Errorf("a column reading one whose items disagree: New = %v, want the column read reported first, containing %q", err, want)
+	}
 }
 
 var jsonInteger = regexp.MustCompile(`^(0|-?[1-9][0-9]*)$`)

record_test.go

@@ -385,7 +385,7 @@ func TestRecordBareReferenceStaysIndependent(t *testing.T) {
 func TestRecordColumnOfOneReferenceIsTheColumnItReads(t *testing.T) {
 	dir := writeData(t, map[string]string{
 		"mid": `{"format":"","score":"{/src.score}"}`,
-		"row": `{"format":"","chain":"{/mid.score}","code":{"format":"{/src.code}","datatype":"integer"},"label":"n={/src.score}","same":"{/src.score}","score":"{/src.score}","text":"{/src.code}"}`,
+		"row": `{"format":"","chain":"{/mid.score}","code":{"format":"{/src.code}","datatype":"integer"},"dot":"{.src.score}","label":"n={/src.score}","mixed":[{"format":"{text}","text":"{/src.score}"},"n/a"],"pick":["{/src.score}",{"format":"7","datatype":"integer"}],"same":"{/src.score}","score":"{/src.score}","text":"{/src.code}"}`,
 		"src": `{"format":"","code":[null,"200","404"],"score":[null,{"format":"{int(1,9)}","datatype":"integer"}]}`,
 	})
 	f := newGenerator(t, dir, WithSeed(1))
@@ -408,22 +408,28 @@ func TestRecordColumnOfOneReferenceIsTheColumnItReads(t *testing.T) {
 			return cols[name].Null == want.Null && cols[name].Value == want.Value
 		}
 		switch {
-		case score.DataType != DataTypeInteger || cols["chain"].DataType != DataTypeInteger || code.DataType != DataTypeInteger || cols["label"].DataType != DataTypeString || cols["text"].DataType != DataTypeString:
-			t.Fatalf("%s: want score, chain and code integer columns, label and text string ones", r.JSON())
+		case score.DataType != DataTypeInteger || cols["chain"].DataType != DataTypeInteger || code.DataType != DataTypeInteger || cols["pick"].DataType != DataTypeInteger || cols["label"].DataType != DataTypeString || cols["mixed"].DataType != DataTypeString || cols["text"].DataType != DataTypeString:
+			t.Fatalf("%s: want score, chain, code and pick integer columns, label, mixed and text string ones", r.JSON())
 		case score.Null == (len(score.Value) == 1 && score.Value >= "1" && score.Value <= "9"):
 			t.Fatalf("score = %+v, want null or a digit from src.score", score)
 		case code.Null == (code.Value == "200" || code.Value == "404"):
 			t.Fatalf("code = %+v, want null or a code from src.code", code)
-		case !agree("same", score) || !agree("chain", score) || !agree("text", code):
+		case !agree("same", score) || !agree("chain", score) || !agree("dot", score) || !agree("text", code):
 			t.Fatalf("%s: want every read of one src column one draw, through mid too", r.JSON())
+		case cols["pick"].Value != "7" && !agree("pick", score), cols["mixed"].Null || cols["mixed"].Value != "n/a" && cols["mixed"].Value != score.Value:
+			t.Fatalf("pick = %+v, mixed = %+v beside score %+v: want pick 7 or the score's draw, mixed n/a or the score's text", cols["pick"], cols["mixed"], score)
 		case cols["label"].Null || cols["label"].Value != "n="+score.Value:
 			t.Fatalf("label = %+v beside score %+v, want the text of the read, a null as \"\"", cols["label"], score)
 		case strings.Contains(r.JSON(), `"score":null`) != score.Null:
 			t.Fatalf("JSON() = %s, want a null score written null", r.JSON())
 		}
-		ic := inline.Fake().Columns()[0]
-		if ic.DataType != DataTypeInteger || ic.Null == (len(ic.Value) == 1) {
-			t.Fatalf("inline score = %+v, want an integer column, null or a digit", ic)
+		ir := inline.Fake()
+		ic, sqlValue := ir.Columns()[0], ir.Columns()[0].Value
+		if ic.Null {
+			sqlValue = "NULL"
+		}
+		if ic.DataType != DataTypeInteger || ic.Null == (len(ic.Value) == 1) || ir.SQLInsert("t") != `INSERT INTO "t" ("score") VALUES (`+sqlValue+`);` || ir.CSVLine() != ic.Value {
+			t.Fatalf("inline score = %+v written %s and %q, want an integer column, NULL and an empty field or a bare digit", ic, ir.SQLInsert("t"), ir.CSVLine())
 		}
 		for name, c := range map[string]Column{"code": code, "inline": ic, "score": score} {
 			if c.Null {

struct_test.go

@@ -54,7 +54,8 @@ func structData(t *testing.T) *Generator {
 	return newGenerator(t, writeData(t, map[string]string{
 		"person": `[{"format":"{first} {last}","first":"Ada","last":"Lovelace"},{"format":"{first} {last}","first":"Bo","last":"Ek"}]`,
 		"place":  `[{"format":"{city}","city":"Stockholm","zip":"111 22"},{"format":"{city}","city":"Tranås","zip":"573 31"}]`,
-		"src":    `{"format":"","code":[null,"200","404"],"score":[null,{"format":"{int(1,9)}","datatype":"integer"}]}`,
+		"mid":    `{"format":"","score":["{/src.score}",{"format":"5","datatype":"integer"}]}`,
+		"src":    `{"format":"","code":[null,"200","404"],"del":null,"score":[null,{"format":"{int(1,9)}","datatype":"integer"}]}`,
 		"trip":   `{"format":"","leg":[{"format":"{to}","to":"Oslo"},{"format":"{to}","to":"Rome"}]}`,
 	}), WithSeed(1))
 }
@@ -62,15 +63,39 @@ func structData(t *testing.T) *Generator {
 func TestFakeStructFieldTaggedWithAColumnIsThatColumn(t *testing.T) {
 	f := structData(t)
 	nils := map[string]int{}
+	show := func(p any) string {
+		switch p := p.(type) {
+		case *string:
+			if p != nil {
+				return *p
+			}
+		case *int64:
+			if p != nil {
+				return strconv.FormatInt(*p, 10)
+			}
+		}
+		return "nil"
+	}
 	for i := 0; i < 200; i++ {
 		var v struct {
 			Code  *string `fake:"src.code"`
+			Codes *string `fake:"[\"{/src.score}\",\"{/src.code}\"]"`
+			Del   *int64  `fake:"src.del"`
 			Label string  `fake:"n={/src.score}"`
+			Mixed *string `fake:"[\"{/src.score}\",\"x\"]"`
+			Pair  *int64  `fake:"[\"{/src.score}\",\"5\"]"`
 			Score *int64  `fake:"src.score"`
 		}
 		if err := f.FakeStruct(&v); err != nil {
 			t.Fatal(err)
 		}
+		score, code := show(v.Score), show(v.Code)
+		switch {
+		case show(v.Del) != "nil":
+			t.Fatalf("Del = %s, want nil from a column only ever null", show(v.Del))
+		case show(v.Mixed) != "x" && show(v.Mixed) != score, show(v.Pair) != "5" && show(v.Pair) != score, show(v.Codes) != score && show(v.Codes) != code:
+			t.Fatalf("Mixed %s, Pair %s, Codes %s beside score %s and code %s: want each the literal or the draw of the column it reads", show(v.Mixed), show(v.Pair), show(v.Codes), score, code)
+		}
 		switch {
 		case v.Code == nil:
 			nils["code"]++
@@ -209,6 +234,9 @@ func TestFakeStructErrors(t *testing.T) {
 		{&struct {
 			A *bool `fake:"src.score"`
 		}{}, ".A (*bool): {int(1,9)} prints an integer, not a boolean"},
+		{&struct {
+			A int64 `fake:"mid.score"`
+		}{}, "can draw null, which int64 cannot hold; make it *int64"},
 		{&struct {
 			A int `fake:"{digits(3)}"`
 		}{}, ".A (int): {digits(3)} prints text, not an integer"},