Fix PL/pgSQL IF hang and bump tree-sitter-postgres to 1.2.2

Cargo.toml

@@ -11,7 +11,7 @@ categories = ["text-processing", "development-tools"]
 
 [dependencies]
 tree-sitter = "0.26"
-tree-sitter-postgres = "1.2"
+tree-sitter-postgres = "1.2.2"
 
 [dev-dependencies]
 pretty_assertions = "1"

examples/dump_plpgsql.rs

@@ -0,0 +1,28 @@
+use tree_sitter::Parser;
+use tree_sitter_postgres::LANGUAGE_PLPGSQL;
+
+fn print_tree(node: tree_sitter::Node, source: &str, indent: usize) {
+    let kind = node.kind();
+    let text = &source[node.byte_range()];
+    let short = if text.len() > 60 { &text[..60] } else { text };
+    let short = short.replace('\n', "\\n");
+    let pad = "  ".repeat(indent);
+    if node.is_named() {
+        println!("{pad}{kind}: {short:?}");
+    } else {
+        println!("{pad}[{kind}]: {short:?}");
+    }
+    let mut cursor = node.walk();
+    for child in node.children(&mut cursor) {
+        print_tree(child, source, indent + 1);
+    }
+}
+
+fn main() {
+    let path = std::env::args().nth(1).expect("usage: dump_plpgsql <file>");
+    let sql = std::fs::read_to_string(&path).unwrap();
+    let mut parser = Parser::new();
+    parser.set_language(&LANGUAGE_PLPGSQL.into()).unwrap();
+    let tree = parser.parse(sql.trim(), None).unwrap();
+    print_tree(tree.root_node(), sql.trim(), 0);
+}

examples/format_plpgsql_test.rs

@@ -0,0 +1,16 @@
+use libpgfmt::{format_plpgsql, style::Style};
+fn main() {
+    let sql = std::fs::read_to_string(std::env::args().nth(1).unwrap()).unwrap();
+    let style: Style = std::env::args()
+        .nth(2)
+        .unwrap_or("aweber".to_string())
+        .parse()
+        .unwrap();
+    match format_plpgsql(sql.trim(), style) {
+        Ok(f) => println!("{f}"),
+        Err(e) => {
+            eprintln!("Error: {e}");
+            std::process::exit(1);
+        }
+    }
+}

src/formatter/plpgsql.rs

@@ -169,8 +169,9 @@ impl<'a> Formatter<'a> {
                             self.kw("THEN")
                         ));
                         i += 3; // skip cond and THEN
+                    } else {
+                        i += 1; // closing IF (END IF)
                     }
-                    // Closing IF (END IF).
                 }
                 "sql_expression" => {
                     i += 1; // handled with IF/ELSIF

tests/plpgsql_test.rs

@@ -0,0 +1,33 @@
+use libpgfmt::{format_plpgsql, style::Style};
+
+// Regression: a plain `IF ... THEN ... END IF` previously hung forever because
+// format_stmt_if never advanced past the closing `kw_if` of `END IF`.
+#[test]
+fn if_then_end_if_terminates() {
+    let body = "BEGIN\n  IF x = 1\n  THEN\n    v := y;\n  END IF;\nEND";
+    let result = format_plpgsql(body, Style::Aweber).unwrap();
+    let expected = "\
+BEGIN
+  IF x = 1 THEN
+    v := y;
+  END IF;
+END;";
+    assert_eq!(result, expected, "\nGot:\n{result}");
+}
+
+#[test]
+fn if_elsif_else_terminates() {
+    let body = "BEGIN\n  IF a THEN\n    v := 1;\n  ELSIF b THEN\n    v := 2;\n  ELSE\n    v := 3;\n  END IF;\nEND";
+    let result = format_plpgsql(body, Style::Aweber).unwrap();
+    let expected = "\
+BEGIN
+  IF a THEN
+    v := 1;
+  ELSIF b THEN
+    v := 2;
+  ELSE
+    v := 3;
+  END IF;
+END;";
+    assert_eq!(result, expected, "\nGot:\n{result}");
+}