Add test for invalid schemars attributes

schemars/Cargo.toml

@@ -26,6 +26,7 @@ arrayvec = { version = "0.5", default-features = false, optional = true }
 
 [dev-dependencies]
 pretty_assertions = "0.6.1"
+trybuild = "1.0"
 
 [features]
 default = ["derive"]
@@ -36,6 +37,8 @@ impl_json_schema = ["derive"]
 # derive_json_schema will be removed in a later version
 derive_json_schema = ["impl_json_schema"]
 
+ui_test = []
+
 [[test]]
 name = "chrono"
 required-features = ["chrono"]
@@ -64,5 +67,9 @@ required-features = ["arrayvec"]
 name = "schema_for_schema"
 required-features = ["impl_json_schema"]
 
+[[test]]
+name = "ui"
+required-features = ["ui_test"]
+
 [package.metadata.docs.rs]
 all-features = true

schemars/src/gen.rs

@@ -1,7 +1,7 @@
 use crate::flatten::Merge;
 use crate::schema::*;
 use crate::{visit::*, JsonSchema, Map};
-use std::{fmt::Debug, sync::Arc};
+use std::sync::Arc;
 
 /// Settings to customize how Schemas are generated.
 ///

schemars/tests/ui.rs

@@ -0,0 +1,5 @@
+#[test]
+fn ui() {
+    let t = trybuild::TestCases::new();
+    t.compile_fail("tests/ui/*.rs");
+}

schemars/tests/ui/invalid_attrs.rs

@@ -0,0 +1,11 @@
+use schemars::JsonSchema;
+
+#[derive(JsonSchema)]
+#[serde(default = 0, foo, deny_unknown_fields, deny_unknown_fields)]
+pub struct Struct1;
+
+#[derive(JsonSchema)]
+#[schemars(default = 0, foo, deny_unknown_fields, deny_unknown_fields)]
+pub struct Struct2;
+
+fn main() {}

schemars/tests/ui/invalid_attrs.stderr

@@ -0,0 +1,29 @@
+error: expected serde default attribute to be a string: `default = "..."`
+ --> $DIR/invalid_attrs.rs:4:19
+  |
+4 | #[serde(default = 0, foo, deny_unknown_fields, deny_unknown_fields)]
+  |                   ^
+
+error: duplicate serde attribute `deny_unknown_fields`
+ --> $DIR/invalid_attrs.rs:4:48
+  |
+4 | #[serde(default = 0, foo, deny_unknown_fields, deny_unknown_fields)]
+  |                                                ^^^^^^^^^^^^^^^^^^^
+
+error: expected serde default attribute to be a string: `default = "..."`
+ --> $DIR/invalid_attrs.rs:8:22
+  |
+8 | #[schemars(default = 0, foo, deny_unknown_fields, deny_unknown_fields)]
+  |                      ^
+
+error: duplicate serde attribute `deny_unknown_fields`
+ --> $DIR/invalid_attrs.rs:8:51
+  |
+8 | #[schemars(default = 0, foo, deny_unknown_fields, deny_unknown_fields)]
+  |                                                   ^^^^^^^^^^^^^^^^^^^
+
+error: unknown schemars container attribute `foo`
+ --> $DIR/invalid_attrs.rs:8:25
+  |
+8 | #[schemars(default = 0, foo, deny_unknown_fields, deny_unknown_fields)]
+  |                         ^^^

update-tests.sh

@@ -5,7 +5,7 @@ cd schemars
 
 rm -f tests/actual/*.json
 
-cargo test --all-features --no-fail-fast --tests || :
+TRYBUILD=overwrite cargo test --all-features --no-fail-fast --tests || :
 
 if ls tests/actual/*.json 1> /dev/null 2>&1; then
   mv -f tests/actual/*.json tests/expected/