From 269269cff09d30a9e338a07df3d36ee42406f7d0 Mon Sep 17 00:00:00 2001
From: Tom French <15848336+TomAFrench@users.noreply.github.com>
Date: Fri, 24 Feb 2023 11:40:32 +0000
Subject: [PATCH] chore: add test for Keyword::lookup_keyword completeness
 (#906)

---
 Cargo.lock                               | 21 +++++++++++++++++++++
 crates/noirc_frontend/Cargo.toml         |  4 ++++
 crates/noirc_frontend/src/lexer/token.rs | 24 ++++++++++++++++++++++++
 3 files changed, 49 insertions(+)

diff --git a/Cargo.lock b/Cargo.lock
index aade42f6e6..42476cea2a 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2083,6 +2083,8 @@ dependencies = [
  "noirc_errors",
  "rustc-hash",
  "smol_str",
+ "strum",
+ "strum_macros",
  "thiserror",
 ]
 
@@ -2986,6 +2988,25 @@ version = "0.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "73473c0e59e6d5812c5dfe2a064a6444949f089e20eec9a2e5506596494e4623"
 
+[[package]]
+name = "strum"
+version = "0.24.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "063e6045c0e62079840579a7e47a355ae92f60eb74daaf156fb1e84ba164e63f"
+
+[[package]]
+name = "strum_macros"
+version = "0.24.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1e385be0d24f186b4ce2f9982191e7101bb737312ad61c1f2f984f34bcf85d59"
+dependencies = [
+ "heck",
+ "proc-macro2",
+ "quote",
+ "rustversion",
+ "syn",
+]
+
 [[package]]
 name = "subtle"
 version = "2.4.1"
diff --git a/crates/noirc_frontend/Cargo.toml b/crates/noirc_frontend/Cargo.toml
index 254cd6a311..b05601c8ab 100644
--- a/crates/noirc_frontend/Cargo.toml
+++ b/crates/noirc_frontend/Cargo.toml
@@ -17,3 +17,7 @@ chumsky.workspace = true
 thiserror.workspace = true
 smol_str.workspace = true
 rustc-hash = "1.1.0"
+
+[dev-dependencies]
+strum = "0.24"
+strum_macros = "0.24"
\ No newline at end of file
diff --git a/crates/noirc_frontend/src/lexer/token.rs b/crates/noirc_frontend/src/lexer/token.rs
index 75df6e526e..7e6d9b88b3 100644
--- a/crates/noirc_frontend/src/lexer/token.rs
+++ b/crates/noirc_frontend/src/lexer/token.rs
@@ -402,6 +402,7 @@ impl AsRef<str> for Attribute {
 }
 
 #[derive(PartialEq, Eq, Hash, Debug, Copy, Clone, PartialOrd, Ord)]
+#[cfg_attr(test, derive(strum_macros::EnumIter))]
 // Special Keywords allowed in the target language
 pub enum Keyword {
     As,
@@ -502,6 +503,29 @@ impl Keyword {
     }
 }
 
+#[cfg(test)]
+mod keywords {
+    use strum::IntoEnumIterator;
+
+    use super::{Keyword, Token};
+
+    #[test]
+    fn lookup_consistency() {
+        for keyword in Keyword::iter() {
+            let resolved_token =
+                Keyword::lookup_keyword(&format!("{keyword}")).unwrap_or_else(|| {
+                    panic!("Keyword::lookup_keyword couldn't find Keyword {}", keyword)
+                });
+
+            assert_eq!(
+                resolved_token,
+                Token::Keyword(keyword),
+                "Keyword::lookup_keyword returns unexpected Keyword"
+            )
+        }
+    }
+}
+
 pub struct Tokens(pub Vec<SpannedToken>);
 
 impl<'a> From<Tokens>