chore(compiler): add a failing test for #742

crates/apollo-compiler/tests/validation/fragments.rs

@@ -0,0 +1,45 @@
+#[test]
+fn long_fragment_chains_do_not_overflow_stack() {
+    // Build a query that applies thousands of fragments
+    // Validating it would take a lot of recursion and blow the stack
+    let mut query = r#"
+      query Introspection{
+        __schema {
+           types {
+            ...typeFragment1
+          }
+        }
+      }
+    "#
+    .to_string();
+
+    let fragments: usize = 10_000;
+    for i in 1..fragments {
+        query.push_str(&format!(
+            "
+          fragment typeFragment{i} on __Type {{
+            ofType {{
+              ...typeFragment{}
+            }}
+          }}",
+            i + 1
+        ));
+    }
+    query.push_str(&format!(
+        "
+          fragment typeFragment{fragments} on __Type {{
+            ofType {{
+              name
+            }}
+          }}"
+    ));
+
+    let (schema, executable) = apollo_compiler::parse_mixed(
+        format!(
+            "type Query {{ a: Int }}
+            {query}"
+        ),
+        "overflow.graphql",
+    );
+    executable.validate(&schema).unwrap();
+}

crates/apollo-compiler/tests/validation/mod.rs

@@ -1,3 +1,4 @@
+mod fragments;
 mod interface;
 mod object;
 mod operation;