test: add test_schema_conflicts (#254)

borsh/src/schema.rs

@@ -250,7 +250,12 @@ pub fn add_definition(
     match definitions.entry(declaration) {
         Entry::Occupied(occ) => {
             let existing_def = occ.get();
-            assert_eq!(existing_def, &definition, "Redefining type schema for the same type name. Types with the same names are not supported.");
+            assert_eq!(
+                existing_def,
+                &definition,
+                "Redefining type schema for {}. Types with the same names are not supported.",
+                occ.key()
+            );
         }
         Entry::Vacant(vac) => {
             vac.insert(definition);

borsh/tests/test_schema_conflict.rs

@@ -0,0 +1,177 @@
+#![cfg_attr(not(feature = "std"), no_std)]
+#![cfg(feature = "unstable__schema")]
+
+#[cfg(feature = "std")]
+use std::collections::{BTreeMap, BTreeSet};
+
+#[cfg(not(feature = "std"))]
+extern crate alloc;
+#[cfg(not(feature = "std"))]
+use alloc::{
+    collections::{BTreeMap, BTreeSet},
+    format,
+    string::ToString,
+    vec::Vec,
+};
+
+use borsh::schema::{add_definition, Declaration, Definition, Fields};
+use borsh::BorshSchema;
+
+struct ConflictingSchema;
+
+impl BorshSchema for ConflictingSchema {
+    #[inline]
+    fn add_definitions_recursively(definitions: &mut BTreeMap<Declaration, Definition>) {
+        let fields = Fields::Empty;
+        let def = Definition::Struct { fields };
+        add_definition(Self::declaration(), def, definitions);
+    }
+    #[inline]
+    fn declaration() -> Declaration {
+        "i64".into()
+    }
+}
+
+#[test]
+#[should_panic(expected = "Redefining type schema for i64")]
+fn test_conflict() {
+    let mut defs = Default::default();
+    <Vec<i64> as borsh::BorshSchema>::add_definitions_recursively(&mut defs);
+
+    <ConflictingSchema as borsh::BorshSchema>::add_definitions_recursively(&mut defs);
+}
+
+#[test]
+#[should_panic(expected = "Redefining type schema for i64")]
+fn test_implicit_conflict_vec() {
+    let mut defs = Default::default();
+    <Vec<i64> as borsh::BorshSchema>::add_definitions_recursively(&mut defs);
+    <Vec<ConflictingSchema> as borsh::BorshSchema>::add_definitions_recursively(&mut defs);
+}
+
+#[test]
+#[should_panic(expected = "Redefining type schema for i64")]
+fn test_implicit_conflict_range() {
+    let mut defs = Default::default();
+    <core::ops::Range<i64> as borsh::BorshSchema>::add_definitions_recursively(&mut defs);
+    <core::ops::Range<ConflictingSchema> as borsh::BorshSchema>::add_definitions_recursively(
+        &mut defs,
+    );
+}
+
+#[test]
+#[should_panic(expected = "Redefining type schema for i64")]
+fn test_implicit_conflict_slice() {
+    let mut defs = Default::default();
+    <[i64] as borsh::BorshSchema>::add_definitions_recursively(&mut defs);
+    <[ConflictingSchema] as borsh::BorshSchema>::add_definitions_recursively(&mut defs);
+}
+
+#[test]
+#[should_panic(expected = "Redefining type schema for i64")]
+fn test_implicit_conflict_array() {
+    let mut defs = Default::default();
+    <[i64; 10] as borsh::BorshSchema>::add_definitions_recursively(&mut defs);
+    <[ConflictingSchema; 10] as borsh::BorshSchema>::add_definitions_recursively(&mut defs);
+}
+
+#[test]
+#[should_panic(expected = "Redefining type schema for i64")]
+fn test_implicit_conflict_option() {
+    let mut defs = Default::default();
+    <Option<i64> as borsh::BorshSchema>::add_definitions_recursively(&mut defs);
+    <Option<ConflictingSchema> as borsh::BorshSchema>::add_definitions_recursively(&mut defs);
+}
+
+#[allow(unused)]
+#[derive(borsh::BorshSchema)]
+struct GenericStruct<T> {
+    field: T,
+}
+
+#[test]
+fn test_implicit_conflict_struct() {
+    let mut defs = Default::default();
+    <GenericStruct<i64> as borsh::BorshSchema>::add_definitions_recursively(&mut defs);
+    <GenericStruct<ConflictingSchema> as borsh::BorshSchema>::add_definitions_recursively(
+        &mut defs,
+    );
+    // NOTE: the contents of `defs` depend on the order of 2 above lines
+    // this loophole is needed to enable derives for recursive structs/enums
+}
+
+#[allow(unused)]
+#[derive(borsh::BorshSchema)]
+struct SelfConflictingStruct {
+    field_1: i64,
+    field_2: ConflictingSchema,
+}
+
+#[test]
+#[should_panic(expected = "Redefining type schema for i64")]
+fn test_implicit_conflict_self_conflicting_struct() {
+    let mut defs = Default::default();
+    <SelfConflictingStruct as borsh::BorshSchema>::add_definitions_recursively(&mut defs);
+}
+
+#[allow(unused)]
+#[derive(borsh::BorshSchema)]
+enum GenericEnum<T> {
+    A { field: T },
+    B(u64),
+}
+
+#[test]
+fn test_implicit_conflict_enum() {
+    let mut defs = Default::default();
+    <GenericEnum<i64> as borsh::BorshSchema>::add_definitions_recursively(&mut defs);
+    <GenericEnum<ConflictingSchema> as borsh::BorshSchema>::add_definitions_recursively(&mut defs);
+    // NOTE: the contents of `defs` depend on the order of 2 above lines
+    // this loophole is needed to enable derives for recursive structs/enums
+}
+
+#[allow(unused)]
+#[derive(borsh::BorshSchema)]
+enum SelfConflictingEnum {
+    A { field: i64 },
+    B { field: ConflictingSchema },
+}
+
+#[test]
+#[should_panic(expected = "Redefining type schema for i64")]
+fn test_implicit_conflict_self_conflicting_enum() {
+    let mut defs = Default::default();
+    <SelfConflictingEnum as borsh::BorshSchema>::add_definitions_recursively(&mut defs);
+}
+
+#[test]
+#[should_panic(expected = "Redefining type schema for i64")]
+fn test_implicit_conflict_result() {
+    let mut defs = Default::default();
+    <Result<u8, i64> as borsh::BorshSchema>::add_definitions_recursively(&mut defs);
+    <Result<u8, ConflictingSchema> as borsh::BorshSchema>::add_definitions_recursively(&mut defs);
+}
+
+#[test]
+#[should_panic(expected = "Redefining type schema for i64")]
+fn test_implicit_conflict_btreemap() {
+    let mut defs = Default::default();
+    <BTreeMap<i64, u8> as borsh::BorshSchema>::add_definitions_recursively(&mut defs);
+    <BTreeMap<ConflictingSchema, u8> as borsh::BorshSchema>::add_definitions_recursively(&mut defs);
+}
+
+#[test]
+#[should_panic(expected = "Redefining type schema for i64")]
+fn test_implicit_conflict_btreeset() {
+    let mut defs = Default::default();
+    <BTreeSet<i64> as borsh::BorshSchema>::add_definitions_recursively(&mut defs);
+    <BTreeSet<ConflictingSchema> as borsh::BorshSchema>::add_definitions_recursively(&mut defs);
+}
+
+#[test]
+#[should_panic(expected = "Redefining type schema for i64")]
+fn test_implicit_conflict_tuple() {
+    let mut defs = Default::default();
+    <(i64, u8) as borsh::BorshSchema>::add_definitions_recursively(&mut defs);
+    <(ConflictingSchema, u8) as borsh::BorshSchema>::add_definitions_recursively(&mut defs);
+}