feat: Readable diffs (#4600)

# Motivation
When a `std::assert_eq!()` fails, it can be quite hard to see the
difference.

# Changes
* Use `pretty_assertions::assert_eq()` instead of `std::assert_eq()`

# Tests
* Library security and code quality: I had a quick look through the
library and its dependencies. It has few dependencies (2) and both
dependencies are minimal.
* Licencing: The license is the standard BSD/apache dual license used in
most Rust projects.
* `pretty_assertions` is already used extensively in the `dfinity/ic`
repository.

# Todos

- [x] Add entry to changelog (if necessary).

CHANGELOG-Nns-Dapp-unreleased.md

@@ -18,6 +18,7 @@ proposal is successful, the changes it released will be moved from this file to
 #### Changed
 
 * Refactored `icpAccountsStore` to be derived from separate stores.
+* More readable error messages if `assert_eq` fails in tests.
 * Wording changes for ineligible neurons description.
 
 #### Deprecated

clippy.toml

@@ -1,9 +1,10 @@
 disallowed-macros = [
-    "std::print",
-    "std::println",
-    "std::eprint",
-    "std::eprintln",
+    { path = "std::print", reason = "Use ic_cdk::print instead" },
+    { path = "std::println", reason = "Use ic_cdk::println instead" },
+    { path = "std::eprint", reason = "Use ic_cdk::eprint instead" },
+    { path = "std::eprintln", reason = "Use ic_cdk::eprintln instead" },
+    { path = "std::assert_eq", reason = "Use pretty_assertions::assert_eq instead" },
 ]
 disallowed-methods = [
-    "dfn_core::api::print",
+    { path = "dfn_core::api::print", reason = "Use ic_cdk::print or ic_cdk::println instead" },
 ]

rs/backend/Cargo.toml

@@ -51,6 +51,7 @@ proposals = { path = "../proposals" }
 [dev-dependencies]
 anyhow = "1.0.75"
 maplit = "1.0.2"
+pretty_assertions = "1.4.0"
 proptest = "1.0.0"
 rand = "0.8.5"
 

rs/backend/src/accounts_store/schema/label_serialization/tests.rs

@@ -2,6 +2,7 @@
 
 use super::*;
 use crate::accounts_store::schema::SchemaLabel;
+use pretty_assertions::assert_eq;
 use strum::IntoEnumIterator;
 
 #[test]

rs/backend/src/accounts_store/schema/proxy/tests.rs

@@ -1,4 +1,5 @@
 use ic_stable_structures::memory_manager;
+use pretty_assertions::assert_eq;
 use proptest::proptest;
 use rand::seq::IteratorRandom;
 use rand::{Rng, SeedableRng};

rs/backend/src/accounts_store/schema/tests.rs

@@ -2,6 +2,7 @@
 
 use super::super::{AccountIdentifier, CanisterId, NamedCanister, PrincipalId};
 use super::*;
+use pretty_assertions::assert_eq;
 use std::collections::{BTreeMap, BTreeSet, HashMap};
 
 /// Creates a toy canister.

rs/backend/src/accounts_store/tests.rs

@@ -3,6 +3,7 @@ use super::*;
 use crate::accounts_store::toy_data::{toy_account, ToyAccountSize};
 use crate::multi_part_transactions_processor::MultiPartTransactionToBeProcessed;
 use icp_ledger::Tokens;
+use pretty_assertions::assert_eq;
 use std::str::FromStr;
 
 const TEST_ACCOUNT_1: &str = "h4a5i-5vcfo-5rusv-fmb6m-vrkia-mjnkc-jpoow-h5mam-nthnm-ldqlr-bqe";

rs/backend/src/assets.rs

@@ -19,6 +19,9 @@ use std::collections::HashMap;
 use std::io::prelude::*;
 use std::io::Read;
 
+#[cfg(test)]
+use pretty_assertions::assert_eq;
+
 type HeaderField = (String, String);
 
 #[derive(Clone, Debug, CandidType, Deserialize)]

rs/backend/src/multi_part_transactions_processor.rs

@@ -56,6 +56,7 @@ impl MultiPartTransactionsProcessor {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use pretty_assertions::assert_eq;
     use std::str::FromStr;
 
     const TEST_ACCOUNT_1: &str = "h4a5i-5vcfo-5rusv-fmb6m-vrkia-mjnkc-jpoow-h5mam-nthnm-ldqlr-bqe";

rs/backend/src/perf/tests.rs

@@ -1,5 +1,6 @@
 use super::PerformanceCounts;
 use crate::state::StableState;
+use pretty_assertions::assert_eq;
 
 /// Given valid performance data, it should serialize and be parsed back to the original.
 #[test]

rs/backend/src/state/partitions/schemas/tests.rs

@@ -2,6 +2,7 @@
 use super::*;
 #[cfg(test)]
 use ic_stable_structures::memory_manager::MemoryManager;
+use pretty_assertions::assert_eq;
 #[cfg(test)]
 use std::rc::Rc;
 use strum::IntoEnumIterator;

rs/backend/src/state/partitions/tests.rs

@@ -6,6 +6,7 @@ use crate::{
 };
 use ic_cdk::api::stable::WASM_PAGE_SIZE_IN_BYTES;
 use ic_crypto_sha::Sha256;
+use pretty_assertions::assert_eq;
 use std::rc::Rc;
 
 #[test]

rs/backend/src/state/tests.rs

@@ -6,6 +6,7 @@ use crate::{
     },
 };
 use ic_stable_structures::{DefaultMemoryImpl, VectorMemory};
+use pretty_assertions::assert_eq;
 use proptest::proptest;
 use std::cell::RefCell;
 use strum::IntoEnumIterator;

rs/proposals/Cargo.toml

@@ -29,3 +29,4 @@ idl2json = "0.8.7"
 
 [dev-dependencies]
 anyhow = "1.0.75"
+pretty_assertions = "1.4.0"

rs/sns_aggregator/Cargo.toml

@@ -29,5 +29,8 @@ serde_derive = "1.0.126"
 serde_json = "1.0.108"
 sha2 = "0.10.8"
 
+[dev-dependencies]
+pretty_assertions = "1.4.0"
+
 [features]
 reconfigurable = []