diff --git a/.cargo_vcs_info.json b/.cargo_vcs_info.json
index 9388b50..eb7e2b0 100644
--- a/.cargo_vcs_info.json
+++ b/.cargo_vcs_info.json
@@ -1,5 +1,5 @@
 {
   "git": {
-    "sha1": "e40ec3e4243f95b39a42bcc9049551b62c3058a0"
+    "sha1": "ff9b0ef7ca5a93f8fb10baba52996e755500546f"
   }
 }
diff --git a/Android.bp b/Android.bp
index ef76cb6..43cb97d 100644
--- a/Android.bp
+++ b/Android.bp
@@ -1,4 +1,4 @@
-// This file is generated by cargo2android.py --run --dependencies --device --tests.
+// This file is generated by cargo2android.py --config cargo2android.json.
 // Do not modify this file as changes will be overridden on upgrade.
 
 package {
@@ -22,6 +22,8 @@
     name: "libtokio_test",
     host_supported: true,
     crate_name: "tokio_test",
+    cargo_env_compat: true,
+    cargo_pkg_version: "0.4.2",
     srcs: ["src/lib.rs"],
     edition: "2018",
     rustlibs: [
@@ -34,38 +36,10 @@
 }
 
 rust_defaults {
-    name: "tokio-test_defaults",
+    name: "tokio-test_test_defaults",
     crate_name: "tokio_test",
-    srcs: ["src/lib.rs"],
-    test_suites: ["general-tests"],
-    auto_gen_config: true,
-    edition: "2018",
-    rustlibs: [
-        "libasync_stream",
-        "libbytes",
-        "libfutures_core",
-        "libfutures_util",
-        "libtokio",
-        "libtokio_stream",
-    ],
-}
-
-rust_test_host {
-    name: "tokio-test_host_test_src_lib",
-    defaults: ["tokio-test_defaults"],
-    test_options: {
-        unit_test: true,
-    },
-}
-
-rust_test {
-    name: "tokio-test_device_test_src_lib",
-    defaults: ["tokio-test_defaults"],
-}
-
-rust_defaults {
-    name: "tokio-test_defaults_tokio_test",
-    crate_name: "tokio_test",
+    cargo_env_compat: true,
+    cargo_pkg_version: "0.4.2",
     test_suites: ["general-tests"],
     auto_gen_config: true,
     edition: "2018",
@@ -80,9 +54,10 @@
     ],
 }
 
-rust_test_host {
-    name: "tokio-test_host_test_tests_block_on",
-    defaults: ["tokio-test_defaults_tokio_test"],
+rust_test {
+    name: "tokio-test_test_tests_block_on",
+    defaults: ["tokio-test_test_defaults"],
+    host_supported: true,
     srcs: ["tests/block_on.rs"],
     test_options: {
         unit_test: true,
@@ -90,14 +65,9 @@
 }
 
 rust_test {
-    name: "tokio-test_device_test_tests_block_on",
-    defaults: ["tokio-test_defaults_tokio_test"],
-    srcs: ["tests/block_on.rs"],
-}
-
-rust_test_host {
-    name: "tokio-test_host_test_tests_io",
-    defaults: ["tokio-test_defaults_tokio_test"],
+    name: "tokio-test_test_tests_io",
+    defaults: ["tokio-test_test_defaults"],
+    host_supported: true,
     srcs: ["tests/io.rs"],
     test_options: {
         unit_test: true,
@@ -105,58 +75,11 @@
 }
 
 rust_test {
-    name: "tokio-test_device_test_tests_io",
-    defaults: ["tokio-test_defaults_tokio_test"],
-    srcs: ["tests/io.rs"],
-}
-
-rust_test_host {
-    name: "tokio-test_host_test_tests_macros",
-    defaults: ["tokio-test_defaults_tokio_test"],
+    name: "tokio-test_test_tests_macros",
+    defaults: ["tokio-test_test_defaults"],
+    host_supported: true,
     srcs: ["tests/macros.rs"],
     test_options: {
         unit_test: true,
     },
 }
-
-rust_test {
-    name: "tokio-test_device_test_tests_macros",
-    defaults: ["tokio-test_defaults_tokio_test"],
-    srcs: ["tests/macros.rs"],
-}
-
-// dependent_library ["feature_list"]
-//   async-stream-0.3.0
-//   async-stream-impl-0.3.0
-//   autocfg-1.0.1
-//   bytes-1.0.1 "default,std"
-//   cfg-if-1.0.0
-//   futures-core-0.3.13 "alloc,default,std"
-//   futures-macro-0.3.13
-//   futures-task-0.3.13 "alloc,std"
-//   futures-util-0.3.13 "alloc,async-await,async-await-macro,default,futures-macro,proc-macro-hack,proc-macro-nested,slab,std"
-//   instant-0.1.9
-//   libc-0.2.92 "default,std"
-//   lock_api-0.4.2
-//   log-0.4.14
-//   memchr-2.3.4 "default,std"
-//   mio-0.7.11 "default,net,os-ext,os-poll,os-util,tcp,udp,uds"
-//   num_cpus-1.13.0
-//   once_cell-1.7.2 "alloc,default,race,std"
-//   parking_lot-0.11.1 "default"
-//   parking_lot_core-0.8.3
-//   pin-project-lite-0.2.6
-//   pin-utils-0.1.0
-//   proc-macro-hack-0.5.19
-//   proc-macro-nested-0.1.7
-//   proc-macro2-1.0.26 "default,proc-macro"
-//   quote-1.0.9 "default,proc-macro"
-//   scopeguard-1.1.0
-//   signal-hook-registry-1.3.0
-//   slab-0.4.2
-//   smallvec-1.6.1
-//   syn-1.0.68 "clone-impls,default,derive,extra-traits,full,parsing,printing,proc-macro,quote,visit-mut"
-//   tokio-1.4.0 "bytes,default,fs,full,io-std,io-util,libc,macros,memchr,mio,net,num_cpus,once_cell,parking_lot,process,rt,rt-multi-thread,signal,signal-hook-registry,sync,test-util,time,tokio-macros,winapi"
-//   tokio-macros-1.1.0
-//   tokio-stream-0.1.5 "default,time"
-//   unicode-xid-0.2.1 "default"
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3fba3ce..5b1786f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,9 @@
+# 0.4.2 (May 14, 2021)
+
+- test: add `assert_elapsed!` macro ([#3728])
+
+[#3728]: https://github.com/tokio-rs/tokio/pull/3728
+
 # 0.4.1 (March 10, 2021)
 
 - Fix `io::Mock` to be `Send` and `Sync` ([#3594])
diff --git a/Cargo.toml b/Cargo.toml
index 6dc1d0c..1ebd109 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -13,11 +13,11 @@
 [package]
 edition = "2018"
 name = "tokio-test"
-version = "0.4.1"
+version = "0.4.2"
 authors = ["Tokio Contributors <team@tokio.rs>"]
 description = "Testing utilities for Tokio- and futures-based code\n"
 homepage = "https://tokio.rs"
-documentation = "https://docs.rs/tokio-test/0.4.1/tokio_test"
+documentation = "https://docs.rs/tokio-test/0.4.2/tokio_test"
 categories = ["asynchronous", "testing"]
 license = "MIT"
 repository = "https://github.com/tokio-rs/tokio"
diff --git a/Cargo.toml.orig b/Cargo.toml.orig
index 2691c89..55d5aaf 100644
--- a/Cargo.toml.orig
+++ b/Cargo.toml.orig
@@ -6,13 +6,13 @@
 #   - Cargo.toml
 # - Update CHANGELOG.md.
 # - Create "tokio-test-0.4.x" git tag.
-version = "0.4.1"
+version = "0.4.2"
 edition = "2018"
 authors = ["Tokio Contributors <team@tokio.rs>"]
 license = "MIT"
 repository = "https://github.com/tokio-rs/tokio"
 homepage = "https://tokio.rs"
-documentation = "https://docs.rs/tokio-test/0.4.1/tokio_test"
+documentation = "https://docs.rs/tokio-test/0.4.2/tokio_test"
 description = """
 Testing utilities for Tokio- and futures-based code
 """
diff --git a/LICENSE b/LICENSE
index 243fcd6..ffa38bb 100644
--- a/LICENSE
+++ b/LICENSE
@@ -1,4 +1,4 @@
-Copyright (c) 2020 Tokio Contributors
+Copyright (c) 2021 Tokio Contributors
 
 Permission is hereby granted, free of charge, to any
 person obtaining a copy of this software and associated
diff --git a/METADATA b/METADATA
index 22032a7..f1e1ef3 100644
--- a/METADATA
+++ b/METADATA
@@ -7,13 +7,13 @@
   }
   url {
     type: ARCHIVE
-    value: "https://static.crates.io/crates/tokio-test/tokio-test-0.4.1.crate"
+    value: "https://static.crates.io/crates/tokio-test/tokio-test-0.4.2.crate"
   }
-  version: "0.4.1"
+  version: "0.4.2"
   license_type: NOTICE
   last_upgrade_date {
     year: 2021
-    month: 4
-    day: 2
+    month: 5
+    day: 19
   }
 }
diff --git a/TEST_MAPPING b/TEST_MAPPING
index 73ad094..f2e3379 100644
--- a/TEST_MAPPING
+++ b/TEST_MAPPING
@@ -1,113 +1,30 @@
 // Generated by update_crate_tests.py for tests that depend on this crate.
 {
+  "imports": [
+    {
+      "path": "external/rust/crates/tokio"
+    }
+  ],
   "presubmit": [
     {
-      "name": "tokio-test_device_test_src_lib"
+      "name": "tokio-test_test_tests_block_on"
     },
     {
-      "name": "tokio-test_device_test_tests_block_on"
+      "name": "tokio-test_test_tests_io"
     },
     {
-      "name": "tokio-test_device_test_tests_io"
+      "name": "tokio-test_test_tests_macros"
+    }
+  ],
+  "presubmit-rust": [
+    {
+      "name": "tokio-test_test_tests_block_on"
     },
     {
-      "name": "tokio-test_device_test_tests_macros"
+      "name": "tokio-test_test_tests_io"
     },
     {
-      "name": "tokio_device_test_tests_buffered"
-    },
-    {
-      "name": "tokio_device_test_tests_io_async_read"
-    },
-    {
-      "name": "tokio_device_test_tests_io_copy_bidirectional"
-    },
-    {
-      "name": "tokio_device_test_tests_io_lines"
-    },
-    {
-      "name": "tokio_device_test_tests_io_mem_stream"
-    },
-    {
-      "name": "tokio_device_test_tests_io_read"
-    },
-    {
-      "name": "tokio_device_test_tests_io_read_buf"
-    },
-    {
-      "name": "tokio_device_test_tests_io_read_to_end"
-    },
-    {
-      "name": "tokio_device_test_tests_io_take"
-    },
-    {
-      "name": "tokio_device_test_tests_io_write"
-    },
-    {
-      "name": "tokio_device_test_tests_io_write_all"
-    },
-    {
-      "name": "tokio_device_test_tests_io_write_buf"
-    },
-    {
-      "name": "tokio_device_test_tests_io_write_int"
-    },
-    {
-      "name": "tokio_device_test_tests_macros_join"
-    },
-    {
-      "name": "tokio_device_test_tests_no_rt"
-    },
-    {
-      "name": "tokio_device_test_tests_rt_basic"
-    },
-    {
-      "name": "tokio_device_test_tests_rt_threaded"
-    },
-    {
-      "name": "tokio_device_test_tests_sync_barrier"
-    },
-    {
-      "name": "tokio_device_test_tests_sync_broadcast"
-    },
-    {
-      "name": "tokio_device_test_tests_sync_errors"
-    },
-    {
-      "name": "tokio_device_test_tests_sync_mpsc"
-    },
-    {
-      "name": "tokio_device_test_tests_sync_mutex_owned"
-    },
-    {
-      "name": "tokio_device_test_tests_sync_rwlock"
-    },
-    {
-      "name": "tokio_device_test_tests_sync_watch"
-    },
-    {
-      "name": "tokio_device_test_tests_task_local"
-    },
-    {
-      "name": "tokio_device_test_tests_task_local_set"
-    },
-    {
-      "name": "tokio_device_test_tests_tcp_accept"
-    },
-    {
-      "name": "tokio_device_test_tests_tcp_echo"
-    },
-    {
-      "name": "tokio_device_test_tests_tcp_into_std"
-    },
-    {
-      "name": "tokio_device_test_tests_tcp_shutdown"
-    },
-    {
-      "name": "tokio_device_test_tests_time_rt"
-    },
-    {
-      "name": "tokio_device_test_tests_uds_split"
+      "name": "tokio-test_test_tests_macros"
     }
   ]
 }
diff --git a/cargo2android.json b/cargo2android.json
new file mode 100644
index 0000000..d36fb44
--- /dev/null
+++ b/cargo2android.json
@@ -0,0 +1,5 @@
+{
+  "device": true,
+  "run": true,
+  "tests": true
+}
\ No newline at end of file
diff --git a/src/macros.rs b/src/macros.rs
index 299bd77..7ca7345 100644
--- a/src/macros.rs
+++ b/src/macros.rs
@@ -259,3 +259,37 @@
         }
     }};
 }
+
+/// Asserts that an exact duration has elapsed since since the start instant ±1ms.
+///
+/// ```rust
+/// use tokio::time::{self, Instant};
+/// use std::time::Duration;
+/// use tokio_test::assert_elapsed;
+/// # async fn test_time_passed() {
+///
+/// let start = Instant::now();
+/// let dur = Duration::from_millis(50);
+/// time::sleep(dur).await;
+/// assert_elapsed!(start, dur);
+/// # }
+/// ```
+///
+/// This 1ms buffer is required because Tokio's hashed-wheel timer has finite time resolution and
+/// will not always sleep for the exact interval.
+#[macro_export]
+macro_rules! assert_elapsed {
+    ($start:expr, $dur:expr) => {{
+        let elapsed = $start.elapsed();
+        // type ascription improves compiler error when wrong type is passed
+        let lower: std::time::Duration = $dur;
+
+        // Handles ms rounding
+        assert!(
+            elapsed >= lower && elapsed <= lower + std::time::Duration::from_millis(1),
+            "actual = {:?}, expected = {:?}",
+            elapsed,
+            lower
+        );
+    }};
+}