fix(syntax): accept function calls nested up to 256 deep

coverage/syntax/receipt-disagreements.toml

@@ -136,7 +136,6 @@ other_receipts_contradicted = [
   "sf.ddl.create-iceberg-table.table.kdeb38bc667b1",
   "sf.expressions.snowflake-db-classes.k9eccc2186fa2",
   "sf.functions.abs.k6169455e23b9",
-  "sf.functions.abs.k93f76764032f",
   "sf.functions.acos.k9277749f1514",
   "sf.functions.acosh.k2bfcf40e4874",
   "sf.functions.ai-summarize-agg.k96152ee79950",
@@ -173,7 +172,6 @@ other_receipts_contradicted = [
   "sf.functions.ceil.kadb89c6ce35e",
   "sf.functions.check-xml.check-xml.kebab6f35e2a9",
   "sf.functions.chr.ke91db843fd30",
-  "sf.functions.coalesce.k25882bf706ba",
   "sf.functions.collate.collate.syntax.kd9832a5c1f19",
   "sf.functions.cos.k5ffbc006170e",
   "sf.functions.cosh.k26b88d9dac0b",

crates/sqlquack-syntax-snowflake/src/parser/tests/test_duckdb_syntax.rs

@@ -57,12 +57,19 @@ fn given_parser_depth_limits_when_parsing_then_deep_input_is_refused_by_its_guar
             expected_outcome_part: "Parse error",
         },
         GuardedParseTestCase {
-            description: "the function nesting guard is independent",
-            sql: nested_calls(100, "abs"),
+            description: "the function nesting guard is independent: 257 nested calls are refused",
+            sql: nested_calls(257, "abs"),
             max_parser_depth: None,
             outcome: configured_outcome,
             expected_outcome_part: "E_GUARD_FUNCTION_NESTING_DEPTH_EXCEEDED",
         },
+        GuardedParseTestCase {
+            description: "256 nested calls, deeper than the 100 Snowflake parses, are read",
+            sql: nested_calls(256, "abs"),
+            max_parser_depth: None,
+            outcome: configured_outcome,
+            expected_outcome_part: "parsed",
+        },
         GuardedParseTestCase {
             description: "16 lambda wrappers consume parser depth",
             sql: wrapped_lambda(16),

crates/sqlquack-syntax/src/guard/constants.rs

@@ -10,7 +10,7 @@ pub(crate) const DEFAULT_MAX_AST_DEPTH: usize = 512;
 
 pub(crate) const DEFAULT_MAX_PARENTHESES_DEPTH: usize = 512;
 
-pub(crate) const DEFAULT_MAX_FUNCTION_CALL_DEPTH: usize = 64;
+pub(crate) const DEFAULT_MAX_FUNCTION_CALL_DEPTH: usize = 256;
 
 /// Deepest type nesting, every `[]`, `ARRAY<`, `ARRAY(`, `OBJECT(` or `MAP(` level counted as one.
 pub const MAX_DATA_TYPE_DEPTH: usize = 512;

tools/sqlquack-coverage-check/src/depth/_helpers/analysed.rs

@@ -198,6 +198,12 @@ fn nested_arithmetic(depth: usize) -> String {
     format!("SELECT {value} AS x FROM orders")
 }
 
+fn nested_calls(depth: usize) -> String {
+    let value: String =
+        (0..depth).fold("id".to_owned(), |value, _| format!("COALESCE({value}, 0)"));
+    format!("SELECT {value} AS x FROM orders")
+}
+
 fn scalar_subqueries(depth: usize) -> String {
     let value: String = (0..depth).fold("id".to_owned(), |value, _| {
         format!("(SELECT {value} FROM orders AS o LIMIT 1)")
@@ -243,6 +249,10 @@ pub(crate) fn analysed_constructs() -> Vec<Construct> {
             name: "analysed_arithmetic",
             text: |parser, depth| analysed(parser, depth, nested_arithmetic),
         },
+        Construct {
+            name: "analysed_function_calls",
+            text: |parser, depth| analysed(parser, depth, nested_calls),
+        },
         Construct {
             name: "analysed_scalar_subqueries",
             text: |parser, depth| analysed(parser, depth, scalar_subqueries),