Inject failpoints with the fail library

server/Cargo.lock

@@ -103,6 +103,17 @@ dependencies = [
  "crypto-common",
 ]
 
+[[package]]
+name = "fail"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fe5e43d0f78a42ad591453aedb1d7ae631ce7ee445c7643691055a9ed8d3b01c"
+dependencies = [
+ "log",
+ "once_cell",
+ "rand",
+]
+
 [[package]]
 name = "fallible-iterator"
 version = "0.2.0"
@@ -716,6 +727,7 @@ name = "server"
 version = "0.1.0"
 dependencies = [
  "anyhow",
+ "fail",
  "rand",
  "rusqlite",
  "serde",

server/Cargo.toml

@@ -8,6 +8,7 @@ default-run = "server"
 
 [dependencies]
 anyhow      = { version = "1" }
+fail        = { version = "0.5" }
 rand        = { version = "0.8" }
 rusqlite    = { version = "0.26" }
 serde       = { version = "1.0", features = ["derive"] }

server/src/authentication.rs

@@ -1,4 +1,5 @@
 use crate::errors::{error, fatal, ok, AppResult, FatalError};
+use fail::fail_point;
 use rusqlite::types::{FromSql, FromSqlError, FromSqlResult, ValueRef};
 use serde::{Deserialize, Serialize};
 use std::collections::HashMap;
@@ -179,8 +180,7 @@ pub struct MemoryAuth {
 
 impl AuthenticationDB for MemoryAuth {
     fn create_user(&mut self, username: Username) -> AppResult<UserId, AuthenticationError> {
-        #[cfg(test)]
-        let _ = maybe_fail::<AuthenticationError>(vec![])?;
+        fail_point!("create-user", |_| Err(FatalError::DiskFull));
 
         if self.users.contains_key(&username) {
             return Ok(Err(AuthenticationError::DuplicateUsername));
@@ -310,15 +310,30 @@ impl AuthenticationDB for MemoryAuth {
 #[cfg(test)]
 mod test {
     use super::*;
+    use fail::FailScenario;
+    use std::panic;
 
     fn with_memory_db<F>(test: F)
     where
-        F: Fn(Box<dyn AuthenticationDB>),
+        F: Fn(Box<dyn AuthenticationDB>) -> () + panic::UnwindSafe,
     {
         let authdb: Box<MemoryAuth> = Box::new(Default::default());
         test(authdb);
     }
 
+    fn with_failpoints<F>(failpoints: Vec<&str>, test: F)
+    where
+        F: Fn() -> () + panic::UnwindSafe,
+    {
+        let scenario = FailScenario::setup();
+        for fp in failpoints {
+            fail::cfg(fp, "return()").unwrap();
+        }
+        let result = panic::catch_unwind(test);
+        scenario.teardown();
+        assert!(result.is_ok())
+    }
+
     #[test]
     fn it_can_create_a_user() {
         fn test_case(mut authdb: Box<dyn AuthenticationDB>) {
@@ -331,7 +346,8 @@ mod test {
             assert_eq!(authdb.get_username(&userid).unwrap(), Ok(username));
             assert!(authdb.list_users().unwrap().unwrap().contains(&userid));
         }
-        with_memory_db(test_case);
+
+        with_failpoints(vec![], || with_memory_db(test_case));
     }
 
     #[test]
@@ -347,7 +363,7 @@ mod test {
                 Err(AuthenticationError::DuplicateUsername)
             );
         }
-        with_memory_db(test_case);
+        with_failpoints(vec![], || with_memory_db(test_case));
     }
 
     #[test]
@@ -367,7 +383,7 @@ mod test {
                 .expect("no fatal errors")
                 .expect("to receive a session token");
         }
-        with_memory_db(test_case);
+        with_failpoints(vec![], || with_memory_db(test_case));
     }
 
     #[test]
@@ -397,7 +413,7 @@ mod test {
                 (garrus, garrus_id)
             );
         }
-        with_memory_db(test_case);
+        with_failpoints(vec![], || with_memory_db(test_case));
     }
 
     #[test]
@@ -413,7 +429,7 @@ mod test {
             authdb.authenticate(invite1).unwrap().unwrap();
             authdb.authenticate(invite2).unwrap().unwrap();
         }
-        with_memory_db(test_case);
+        with_failpoints(vec![], || with_memory_db(test_case));
     }
 
     #[test]
@@ -439,7 +455,7 @@ mod test {
                 (username, userid)
             );
         }
-        with_memory_db(test_case);
+        with_failpoints(vec![], || with_memory_db(test_case));
     }
 
     #[test]
@@ -461,7 +477,7 @@ mod test {
             let reuse_result = authdb.authenticate(invitation).expect("no fatal errors");
             assert_eq!(reuse_result, Err(AuthenticationError::InvalidInvitation));
         }
-        with_memory_db(test_case);
+        with_failpoints(vec![], || with_memory_db(test_case));
     }
 
     #[test]
@@ -493,7 +509,7 @@ mod test {
                 Err(AuthenticationError::InvalidInvitation)
             );
         }
-        with_memory_db(test_case);
+        with_failpoints(vec![], || with_memory_db(test_case));
     }
 
     #[test]
@@ -516,7 +532,7 @@ mod test {
                 Err(AuthenticationError::InvalidSession)
             );
         }
-        with_memory_db(test_case);
+        with_failpoints(vec![], || with_memory_db(test_case));
     }
 
     #[test]
@@ -541,6 +557,6 @@ mod test {
                 Err(AuthenticationError::InvalidInvitation)
             );
         }
-        with_memory_db(test_case);
+        with_failpoints(vec![], || with_memory_db(test_case));
     }
 }