Introduce a collections crate w/ deterministic hashmap, hashset in tests

Co-Authored-By: Nathan Sobo <nathan@zed.dev>

crates/buffer/Cargo.toml

@@ -4,19 +4,19 @@ version = "0.1.0"
 edition = "2021"
 
 [features]
-test-support = ["rand", "seahash"]
+test-support = ["rand"]
 
 [dependencies]
 clock = { path = "../clock" }
+collections = { path = "../collections" }
 sum_tree = { path = "../sum_tree" }
 anyhow = "1.0.38"
 arrayvec = "0.7.1"
 log = "0.4"
 rand = { version = "0.8.3", optional = true }
-seahash = { version = "4.1", optional = true }
 smallvec = { version = "1.6", features = ["union"] }
 
 [dev-dependencies]
+collections = { path = "../collections", features = ["test-support"] }
 gpui = { path = "../gpui", features = ["test-support"] }
-seahash = "4.1"
 rand = "0.8.3"

crates/buffer/src/lib.rs

@@ -12,6 +12,7 @@ mod tests;
 pub use anchor::*;
 use anyhow::{anyhow, Result};
 use clock::ReplicaId;
+use collections::{HashMap, HashSet};
 use operation_queue::OperationQueue;
 pub use point::*;
 pub use point_utf16::*;
@@ -31,31 +32,6 @@ use std::{
 pub use sum_tree::Bias;
 use sum_tree::{FilterCursor, SumTree};
 
-#[cfg(any(test, feature = "test-support"))]
-#[derive(Clone, Default)]
-pub struct DeterministicState;
-
-#[cfg(any(test, feature = "test-support"))]
-impl std::hash::BuildHasher for DeterministicState {
-    type Hasher = seahash::SeaHasher;
-
-    fn build_hasher(&self) -> Self::Hasher {
-        seahash::SeaHasher::new()
-    }
-}
-
-#[cfg(any(test, feature = "test-support"))]
-type HashMap<K, V> = std::collections::HashMap<K, V, DeterministicState>;
-
-#[cfg(any(test, feature = "test-support"))]
-type HashSet<T> = std::collections::HashSet<T, DeterministicState>;
-
-#[cfg(not(any(test, feature = "test-support")))]
-type HashMap<K, V> = std::collections::HashMap<K, V>;
-
-#[cfg(not(any(test, feature = "test-support")))]
-type HashSet<T> = std::collections::HashSet<T>;
-
 #[derive(Clone)]
 pub struct Buffer {
     fragments: SumTree<Fragment>,