From 6ed4f2ef380921ae2382f03321b15efc04002a04 Mon Sep 17 00:00:00 2001
From: Steve Dignam <steve@dignam.xyz>
Date: Thu, 4 Dec 2025 22:19:59 -0500
Subject: [PATCH] parser: fix parsing insert select on conflict

We were parsing the on conflict as a join.

rel: https://github.com/sbdchd/squawk/issues/718
---
 crates/squawk_parser/src/grammar.rs           |  2 +-
 crates/squawk_parser/tests/data/ok/insert.sql |  9 ++++
 .../tests/snapshots/tests__insert_ok.snap     | 51 +++++++++++++++++++
 3 files changed, 61 insertions(+), 1 deletion(-)

diff --git a/crates/squawk_parser/src/grammar.rs b/crates/squawk_parser/src/grammar.rs
index 1e0b739f..2e6ed586 100644
--- a/crates/squawk_parser/src/grammar.rs
+++ b/crates/squawk_parser/src/grammar.rs
@@ -3456,7 +3456,7 @@ fn join(p: &mut Parser<'_>) {
     if !opt_from_item(p) {
         p.error("expected from_item");
     }
-    if p.at(ON_KW) {
+    if p.at(ON_KW) && !p.nth_at(1, CONFLICT_KW) {
         on_clause(p);
     } else if p.at(USING_KW) {
         join_using_clause(p);
diff --git a/crates/squawk_parser/tests/data/ok/insert.sql b/crates/squawk_parser/tests/data/ok/insert.sql
index b4e2f8c2..d805d2dc 100644
--- a/crates/squawk_parser/tests/data/ok/insert.sql
+++ b/crates/squawk_parser/tests/data/ok/insert.sql
@@ -91,3 +91,12 @@ INSERT INTO distributors (did, dname) VALUES (10, 'Conrad International')
 
 -- with schema
 insert into s.t (c) values (1);
+
+
+-- regression check for issue #718
+-- we were parsing the `on conflict` as the start of a `join on`
+INSERT INTO t
+SELECT *
+FROM t
+CROSS JOIN f
+ON CONFLICT DO NOTHING;
diff --git a/crates/squawk_parser/tests/snapshots/tests__insert_ok.snap b/crates/squawk_parser/tests/snapshots/tests__insert_ok.snap
index 14c8e826..d337aeea 100644
--- a/crates/squawk_parser/tests/snapshots/tests__insert_ok.snap
+++ b/crates/squawk_parser/tests/snapshots/tests__insert_ok.snap
@@ -1463,4 +1463,55 @@ SOURCE_FILE
             INT_NUMBER "1"
           R_PAREN ")"
   SEMICOLON ";"
+  WHITESPACE "\n\n\n"
+  COMMENT "-- regression check for issue #718"
+  WHITESPACE "\n"
+  COMMENT "-- we were parsing the `on conflict` as the start of a `join on`"
+  WHITESPACE "\n"
+  INSERT
+    INSERT_KW "INSERT"
+    WHITESPACE " "
+    INTO_KW "INTO"
+    WHITESPACE " "
+    PATH
+      PATH_SEGMENT
+        NAME_REF
+          IDENT "t"
+    WHITESPACE "\n"
+    SELECT
+      SELECT_CLAUSE
+        SELECT_KW "SELECT"
+        WHITESPACE " "
+        TARGET_LIST
+          TARGET
+            STAR "*"
+      WHITESPACE "\n"
+      FROM_CLAUSE
+        FROM_KW "FROM"
+        WHITESPACE " "
+        JOIN_EXPR
+          FROM_ITEM
+            NAME_REF
+              IDENT "t"
+          WHITESPACE "\n"
+          JOIN
+            JOIN_CROSS
+              CROSS_KW "CROSS"
+              WHITESPACE " "
+              JOIN_KW "JOIN"
+            WHITESPACE " "
+            FROM_ITEM
+              NAME_REF
+                IDENT "f"
+    WHITESPACE "\n"
+    ON_CONFLICT_CLAUSE
+      ON_KW "ON"
+      WHITESPACE " "
+      CONFLICT_KW "CONFLICT"
+      WHITESPACE " "
+      CONFLICT_DO_NOTHING
+        DO_KW "DO"
+        WHITESPACE " "
+        NOTHING_KW "NOTHING"
+  SEMICOLON ";"
   WHITESPACE "\n"