fix: align PLpgSQL formatting clauses

pkg/format/format_test.go

@@ -107,6 +107,66 @@ func TestFormatMmProcBroken(t *testing.T) {
 	}
 }
 
+func TestFormatIssue1PLpgSQLIndenting(t *testing.T) {
+	src := "CREATE FUNCTION f() RETURNS void LANGUAGE plpgsql AS $$\n" +
+		"DECLARE\n" +
+		"  r_lp record;\n" +
+		"BEGIN\n" +
+		"   if r_lp.total > 0\n" +
+		"      and r_lp.totaldone >= r_lp.total\n" +
+		"    then\n" +
+		"    update core.process u\n" +
+		"      set status = 'done'\n" +
+		"      where u.rid_process = r_lp.rid_process\n" +
+		"        and nv(u.status) <> 'done';\n" +
+		"  elsif r_lp.total > 0\n" +
+		"    then\n" +
+		"    update core.process u\n" +
+		"      set status = 'open'\n" +
+		"      where u.rid_process = r_lp.rid_process\n" +
+		"        and nv(u.status) <> 'open';\n" +
+		"\n" +
+		"  end if;\n" +
+		"$$;\n"
+
+	want := "CREATE FUNCTION f(\n" +
+		")\n" +
+		"RETURNS void\n" +
+		"LANGUAGE plpgsql\n" +
+		"AS\n" +
+		"$$\n" +
+		"DECLARE\n" +
+		"  r_lp record;\n" +
+		"BEGIN\n" +
+		"  if r_lp.total > 0\n" +
+		"      and r_lp.totaldone >= r_lp.total\n" +
+		"  then\n" +
+		"    update core.process u\n" +
+		"    set status = 'done'\n" +
+		"    where\n" +
+		"        u.rid_process = r_lp.rid_process\n" +
+		"      and nv(u.status) <> 'done';\n" +
+		"  elsif r_lp.total > 0\n" +
+		"  then\n" +
+		"    update core.process u\n" +
+		"    set status = 'open'\n" +
+		"    where\n" +
+		"        u.rid_process = r_lp.rid_process\n" +
+		"      and nv(u.status) <> 'open';\n" +
+		"\n" +
+		"  end if;\n" +
+		"$$;\n"
+
+	got := format(src)
+	if got != want {
+		t.Errorf("issue #1 PL/pgSQL indenting\n--- got ---\n%s\n--- want ---\n%s", got, want)
+	}
+	checkDML(t, "issue #1 PL/pgSQL indenting", got)
+	if !semanticallyEqual(src, got) {
+		t.Errorf("issue #1 PL/pgSQL indenting changed semantics")
+	}
+}
+
 func TestCorpusIdempotentAndSafe(t *testing.T) {
 	dir := filepath.Join("..", "..", "testdata", "corpus")
 	entries, err := os.ReadDir(dir)