From b0a2f9994ba2a6d19fdf991351b2fcfde3b3e681 Mon Sep 17 00:00:00 2001
From: Graham Esau <gesau@hotmail.co.uk>
Date: Thu, 4 Jun 2020 19:39:57 +0100
Subject: [PATCH] Error on unknown schemars attr items

---
 CHANGELOG.md                                  |  3 ++
 schemars_derive/src/attr/mod.rs               | 46 +++++++++----------
 schemars_derive/src/attr/schemars_to_serde.rs |  2 +-
 3 files changed, 27 insertions(+), 24 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1a8e4d9..0b38814 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,9 @@
 - `SchemaSettings::bool_schemas` - this has been superseded by the `ReplaceBoolSchemas` visitor
 - `SchemaSettings::allow_ref_siblings` - this has been superseded by the `RemoveRefSiblings` visitor
 
+### Fixed:
+- **BREAKING CHANGE** unknown items in `#[schemars(...)]` attributes now cause a compilation error (https://github.com/GREsau/schemars/issues/18)
+
 ### Deprecated:
 - `make_extensible`, `schema_for_any`, and `schema_for_none` methods on `SchemaGenerator`
 
diff --git a/schemars_derive/src/attr/mod.rs b/schemars_derive/src/attr/mod.rs
index 9bf221c..37919b3 100644
--- a/schemars_derive/src/attr/mod.rs
+++ b/schemars_derive/src/attr/mod.rs
@@ -4,6 +4,7 @@ mod schemars_to_serde;
 pub use schemars_to_serde::process_serde_attrs;
 
 use proc_macro2::{Group, Span, TokenStream, TokenTree};
+use quote::ToTokens;
 use serde_derive_internals::Ctxt;
 use syn::parse::{self, Parse};
 use syn::Meta::{List, NameValue};
@@ -117,31 +118,30 @@ impl Attrs {
                     }
                 }
 
-                Meta(_meta_item) => {
-                    // TODO uncomment this for 0.8.0 (breaking change)
-                    //  https://github.com/GREsau/schemars/issues/18
-                    // if !ignore_errors {
-                    //     let path = meta_item
-                    //         .path()
-                    //         .into_token_stream()
-                    //         .to_string()
-                    //         .replace(' ', "");
-                    //     errors.error_spanned_by(
-                    //         meta_item.path(),
-                    //         format!("unknown schemars container attribute `{}`", path),
-                    //     );
-                    // }
+                _ if ignore_errors => {}
+
+                Meta(meta_item) => {
+                    let is_known_serde_keyword = schemars_to_serde::SERDE_KEYWORDS
+                        .iter()
+                        .any(|k| meta_item.path().is_ident(k));
+                    if !is_known_serde_keyword {
+                        let path = meta_item
+                            .path()
+                            .into_token_stream()
+                            .to_string()
+                            .replace(' ', "");
+                        errors.error_spanned_by(
+                            meta_item.path(),
+                            format!("unknown schemars container attribute `{}`", path),
+                        );
+                    }
                 }
 
-                Lit(_lit) => {
-                    // TODO uncomment this for 0.8.0 (breaking change)
-                    //  https://github.com/GREsau/schemars/issues/18
-                    // if !ignore_errors {
-                    //     errors.error_spanned_by(
-                    //         lit,
-                    //         "unexpected literal in schemars container attribute",
-                    //     );
-                    // }
+                Lit(lit) => {
+                    errors.error_spanned_by(
+                        lit,
+                        "unexpected literal in schemars container attribute",
+                    );
                 }
             }
         }
diff --git a/schemars_derive/src/attr/schemars_to_serde.rs b/schemars_derive/src/attr/schemars_to_serde.rs
index 380a276..bf8d389 100644
--- a/schemars_derive/src/attr/schemars_to_serde.rs
+++ b/schemars_derive/src/attr/schemars_to_serde.rs
@@ -5,7 +5,7 @@ use syn::parse::Parser;
 use syn::{Attribute, Data, Field, Meta, NestedMeta, Variant};
 
 // List of keywords that can appear in #[serde(...)]/#[schemars(...)] attributes which we want serde_derive_internals to parse for us.
-static SERDE_KEYWORDS: &[&str] = &[
+pub(crate) static SERDE_KEYWORDS: &[&str] = &[
     "rename",
     "rename_all",
     "deny_unknown_fields",