feat(format): select_wrap and join_wrap with when_long via Doc-IR

pkg/format/dml.go

@@ -206,6 +206,27 @@ func dmlJoinClause(kwText string, body []cst.Tok, st config.Style) string {
 	if text != "" {
 		line += " " + text
 	}
+	if onIdx := dmlKeywordIdx(body, 0, "on"); onIdx >= 0 && st.JoinWrap != config.WrapNever {
+		nl := st.Newline
+		var b strings.Builder
+		b.WriteString(kwText)
+		if head := dmlInline(body[:onIdx], st); head != "" {
+			b.WriteString(" " + head)
+		}
+		for i, cond := range dmlSplitAndOr(body[onIdx+1:]) {
+			b.WriteString(nl + st.Indent)
+			if i == 0 {
+				b.WriteString(caseText(body[onIdx].Tok, st) + " ")
+			}
+			b.WriteString(strings.ReplaceAll(dmlInline(cond, st), nl, nl+st.Indent))
+		}
+		broken := b.String()
+		if st.JoinWrap == config.WrapAlways || strings.Contains(line, nl) {
+			line = broken
+		} else {
+			line = Render(Group(IfBreak(Text(broken), Text(line))), st.LineWidth, st.Indent, nl)
+		}
+	}
 	if !st.IndentJoin {
 		return line
 	}
@@ -720,16 +741,31 @@ func dmlColListSelect(kwText string, items [][]cst.Tok, st config.Style) string
 	}
 
 	texts := make([]string, len(items))
+	multiline := false
 	for i, item := range items {
 		texts[i] = dmlInline(item, st)
+		if strings.Contains(texts[i], st.Newline) {
+			multiline = true
+		}
 	}
+	flat := kwText + " " + strings.Join(texts, ", ")
 
 	// align_columns / select_align_as: pad expressions so AS and aliases align.
 	if (st.AlignColumns || st.SelectAlignAs) && len(texts) > 1 {
 		texts = alignSelectItems(texts, st)
 	}
 
-	return dmlCommaList(kwText, texts, st)
+	broken := dmlCommaList(kwText, texts, st)
+	if multiline {
+		return broken // an embedded subquery / wrapped CASE can't sit on one line
+	}
+	switch st.SelectWrap {
+	case config.WrapNever:
+		return flat
+	case config.WrapWhenLong:
+		return Render(Group(IfBreak(Text(broken), Text(flat))), st.LineWidth, st.Indent, st.Newline)
+	}
+	return broken
 }
 
 // dmlColListSet formats an UPDATE SET column list with optional set_align_equal.

pkg/format/dml_test.go

@@ -647,3 +647,50 @@ func TestDMLCaseCollapseUsesLineWidth(t *testing.T) {
 		t.Errorf("exceeds 30, should wrap:\n%s", got)
 	}
 }
+
+func TestSelectWrap(t *testing.T) {
+	src := "select a, b, c from t"
+	st := config.Default()
+	if got := File(parser.Parse(src), st); !strings.Contains(got, "\n  ,b") {
+		t.Errorf("default select_wrap=always should list one per line:\n%s", got)
+	}
+	st.SelectWrap = config.WrapNever
+	if got := File(parser.Parse(src), st); !strings.Contains(got, "SELECT a, b, c") {
+		t.Errorf("never:\n%s", got)
+	}
+	st.SelectWrap = config.WrapWhenLong
+	st.LineWidth = 120
+	if got := File(parser.Parse(src), st); !strings.Contains(got, "SELECT a, b, c") {
+		t.Errorf("when_long, short:\n%s", got)
+	}
+	st.LineWidth = 8
+	if got := File(parser.Parse(src), st); !strings.Contains(got, "\n  ,b") {
+		t.Errorf("when_long, long:\n%s", got)
+	}
+}
+
+func TestJoinWrap(t *testing.T) {
+	src := "select a from t join u on t.id = u.id and t.x = u.x"
+	st := config.Default()
+	base := File(parser.Parse(src), st)
+	if !strings.Contains(base, "JOIN u ON t.id = u.id AND t.x = u.x") {
+		t.Fatalf("default join_wrap=never should stay inline:\n%s", base)
+	}
+	st.JoinWrap = config.WrapAlways
+	got := File(parser.Parse(src), st)
+	if !strings.Contains(got, "JOIN u\n  ON t.id = u.id\n  AND t.x = u.x") {
+		t.Errorf("always:\n%s", got)
+	}
+	if twice := File(parser.Parse(got), st); twice != got {
+		t.Errorf("not idempotent:\n%s\n---\n%s", got, twice)
+	}
+	st.JoinWrap = config.WrapWhenLong
+	st.LineWidth = 120
+	if File(parser.Parse(src), st) != base {
+		t.Errorf("when_long short should equal inline")
+	}
+	st.LineWidth = 20
+	if File(parser.Parse(src), st) != got {
+		t.Errorf("when_long long should equal always")
+	}
+}