From 1c11684da5146db5c38d3e5fae240002c8c05efd Mon Sep 17 00:00:00 2001
From: jedel1043 <jedel0124@gmail.com>
Date: Fri, 2 Jun 2023 20:34:09 -0600
Subject: [PATCH] Add example for async module fetches

---
 Cargo.lock                           | 725 ++++++++++++++++++++++++++-
 boa_examples/Cargo.toml              |   3 +
 boa_examples/src/bin/module_fetch.rs | 249 +++++++++
 3 files changed, 953 insertions(+), 24 deletions(-)
 create mode 100644 boa_examples/src/bin/module_fetch.rs

diff --git a/Cargo.lock b/Cargo.lock
index 8345fcb91ac..64d9049715c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -17,6 +17,26 @@ version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f26201604c87b1e01bd3d98f8d5d9a8fcbb815e8cedb41ffccbeb4bf593a35fe"
 
+[[package]]
+name = "aead"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7fc95d1bdb8e6666b2b217308eeeb09f2d6728d104be3e31916cc74d15420331"
+dependencies = [
+ "generic-array",
+]
+
+[[package]]
+name = "aes"
+version = "0.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "884391ef1066acaa41e766ba8f596341b96e93ce34f9a43e7d24bf0a0eaf0561"
+dependencies = [
+ "aes-soft",
+ "aesni",
+ "cipher 0.2.5",
+]
+
 [[package]]
 name = "aes"
 version = "0.7.5"
@@ -24,18 +44,52 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9e8b47f52ea9bae42228d07ec09eb676433d7c4ed1ebdf0f1d1c29ed446f1ab8"
 dependencies = [
  "cfg-if 1.0.0",
- "cipher",
+ "cipher 0.3.0",
  "cpufeatures",
  "opaque-debug",
 ]
 
+[[package]]
+name = "aes-gcm"
+version = "0.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5278b5fabbb9bd46e24aa69b2fdea62c99088e0a950a9be40e3e0101298f88da"
+dependencies = [
+ "aead",
+ "aes 0.6.0",
+ "cipher 0.2.5",
+ "ctr",
+ "ghash",
+ "subtle",
+]
+
+[[package]]
+name = "aes-soft"
+version = "0.6.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "be14c7498ea50828a38d0e24a765ed2effe92a705885b57d029cd67d45744072"
+dependencies = [
+ "cipher 0.2.5",
+ "opaque-debug",
+]
+
+[[package]]
+name = "aesni"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ea2e11f5e94c2f7d386164cc2aa1f97823fed6f259e486940a71c174dd01b0ce"
+dependencies = [
+ "cipher 0.2.5",
+ "opaque-debug",
+]
+
 [[package]]
 name = "ahash"
 version = "0.7.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fcb51a0695d8f838b1ee009b3fbf66bda078cd64590202a864a8f3e8c4315c47"
 dependencies = [
- "getrandom",
+ "getrandom 0.2.9",
  "once_cell",
  "version_check",
 ]
@@ -130,6 +184,12 @@ dependencies = [
  "windows-sys 0.48.0",
 ]
 
+[[package]]
+name = "anyhow"
+version = "1.0.71"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9c7d0618f0e0b7e8ff11427422b64564d5fb0be1940354bfe2e0529b18a9d9b8"
+
 [[package]]
 name = "arbitrary"
 version = "1.3.0"
@@ -139,6 +199,12 @@ dependencies = [
  "derive_arbitrary",
 ]
 
+[[package]]
+name = "arrayvec"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "23b62fc65de8e4e7f52534fb52b0f3ed04746ae267519eef2a83941e8085068b"
+
 [[package]]
 name = "async-channel"
 version = "1.8.0"
@@ -150,6 +216,16 @@ dependencies = [
  "futures-core",
 ]
 
+[[package]]
+name = "async-dup"
+version = "1.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7427a12b8dc09291528cfb1da2447059adb4a257388c2acd6497a79d55cf6f7c"
+dependencies = [
+ "futures-io",
+ "simple-mutex",
+]
+
 [[package]]
 name = "async-executor"
 version = "1.5.1"
@@ -176,6 +252,37 @@ dependencies = [
  "futures-lite",
 ]
 
+[[package]]
+name = "async-global-executor"
+version = "2.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f1b6f5d7df27bd294849f8eec66ecfc63d11814df7a4f5d74168a2394467b776"
+dependencies = [
+ "async-channel",
+ "async-executor",
+ "async-io",
+ "async-lock",
+ "blocking",
+ "futures-lite",
+ "once_cell",
+]
+
+[[package]]
+name = "async-h1"
+version = "2.3.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8101020758a4fc3a7c326cb42aa99e9fa77cbfb76987c128ad956406fe1f70a7"
+dependencies = [
+ "async-channel",
+ "async-dup",
+ "async-std",
+ "futures-core",
+ "http-types",
+ "httparse",
+ "log",
+ "pin-project",
+]
+
 [[package]]
 name = "async-io"
 version = "1.13.0"
@@ -235,12 +342,62 @@ dependencies = [
  "windows-sys 0.48.0",
 ]
 
+[[package]]
+name = "async-std"
+version = "1.12.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "62565bb4402e926b29953c785397c6dc0391b7b446e45008b0049eb43cec6f5d"
+dependencies = [
+ "async-channel",
+ "async-global-executor",
+ "async-io",
+ "async-lock",
+ "crossbeam-utils",
+ "futures-channel",
+ "futures-core",
+ "futures-io",
+ "futures-lite",
+ "gloo-timers",
+ "kv-log-macro",
+ "log",
+ "memchr",
+ "once_cell",
+ "pin-project-lite",
+ "pin-utils",
+ "slab",
+ "wasm-bindgen-futures",
+]
+
 [[package]]
 name = "async-task"
 version = "4.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ecc7ab41815b3c653ccd2978ec3255c81349336702dfdf62ee6f7069b12a3aae"
 
+[[package]]
+name = "async-tls"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d85a97c4a0ecce878efd3f945f119c78a646d8975340bca0398f9bb05c30cc52"
+dependencies = [
+ "futures-core",
+ "futures-io",
+ "rustls",
+ "webpki",
+ "webpki-roots",
+]
+
+[[package]]
+name = "async-trait"
+version = "0.1.68"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b9ccdd8f2a161be9bd5c023df56f1b2a0bd1d83872ae53b71a84a12c9bf6e842"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.18",
+]
+
 [[package]]
 name = "atomic-polyfill"
 version = "1.0.2"
@@ -294,6 +451,18 @@ version = "0.2.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4cbbc9d0964165b47557570cce6c952866c2678457aca742aafc9fb771d30270"
 
+[[package]]
+name = "base64"
+version = "0.12.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3441f0f7b02788e948e47f457ca01f1d7e6d92c693bc132c22b087d3141c03ff"
+
+[[package]]
+name = "base64"
+version = "0.13.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9e1b586273c5702936fe7b7d6896644d8be71e6314cfe09d3167c95f712589e8"
+
 [[package]]
 name = "base64"
 version = "0.21.0"
@@ -339,6 +508,15 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "block-buffer"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4152116fd6e9dadb291ae18fc1ec3575ed6d84c29642d97890f4b4a3417297e4"
+dependencies = [
+ "generic-array",
+]
+
 [[package]]
 name = "block-buffer"
 version = "0.10.4"
@@ -435,7 +613,7 @@ dependencies = [
  "num_enum",
  "once_cell",
  "pollster",
- "rand",
+ "rand 0.8.5",
  "regress",
  "rustc-hash",
  "ryu-js",
@@ -465,6 +643,7 @@ dependencies = [
  "boa_runtime",
  "futures-util",
  "smol",
+ "surf",
 ]
 
 [[package]]
@@ -605,7 +784,7 @@ dependencies = [
  "boa_engine",
  "chrono",
  "console_error_panic_hook",
- "getrandom",
+ "getrandom 0.2.9",
  "wasm-bindgen",
 ]
 
@@ -681,11 +860,11 @@ dependencies = [
  "glob",
  "indicatif",
  "log",
- "rand",
+ "rand 0.8.5",
  "reqwest",
  "serde",
  "serde_json",
- "sha2",
+ "sha2 0.10.6",
  "tar",
  "tempfile",
  "thiserror",
@@ -761,6 +940,15 @@ dependencies = [
  "half",
 ]
 
+[[package]]
+name = "cipher"
+version = "0.2.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "12f8e7987cbd042a63249497f41aed09f8e65add917ea6566effbc56578d6801"
+dependencies = [
+ "generic-array",
+]
+
 [[package]]
 name = "cipher"
 version = "0.3.0"
@@ -925,6 +1113,17 @@ dependencies = [
  "crossbeam-utils",
 ]
 
+[[package]]
+name = "config"
+version = "0.10.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "19b076e143e1d9538dde65da30f8481c2a6c44040edb8e02b9bf1351edb92ce3"
+dependencies = [
+ "lazy_static",
+ "nom",
+ "serde",
+]
+
 [[package]]
 name = "console"
 version = "0.15.5"
@@ -959,6 +1158,23 @@ version = "0.1.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "245097e9a4535ee1e3e3931fcfcd55a796a44c643e8596ff6566d68f09b87bbc"
 
+[[package]]
+name = "cookie"
+version = "0.14.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "03a5d7b21829bc7b4bf4754a978a241ae54ea55a40f92bb20216e54096f4b951"
+dependencies = [
+ "aes-gcm",
+ "base64 0.13.1",
+ "hkdf",
+ "hmac 0.10.1",
+ "percent-encoding",
+ "rand 0.8.5",
+ "sha2 0.9.9",
+ "time 0.2.27",
+ "version_check",
+]
+
 [[package]]
 name = "core-foundation"
 version = "0.9.3"
@@ -997,6 +1213,12 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "cpuid-bool"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dcb25d077389e53838a8158c8e99174c5a9d902dee4904320db714f3c653ffba"
+
 [[package]]
 name = "crc32fast"
 version = "1.3.2"
@@ -1088,6 +1310,16 @@ dependencies = [
  "scopeguard",
 ]
 
+[[package]]
+name = "crossbeam-queue"
+version = "0.3.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d1cfb3ea8a53f37c40dea2c7bedcbd88bdfae54f5e2175d6ecaff1c988353add"
+dependencies = [
+ "cfg-if 1.0.0",
+ "crossbeam-utils",
+]
+
 [[package]]
 name = "crossbeam-utils"
 version = "0.8.15"
@@ -1132,6 +1364,25 @@ dependencies = [
  "typenum",
 ]
 
+[[package]]
+name = "crypto-mac"
+version = "0.10.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bff07008ec701e8028e2ceb8f83f0e4274ee62bd2dbdc4fefff2e9a91824081a"
+dependencies = [
+ "generic-array",
+ "subtle",
+]
+
+[[package]]
+name = "ctr"
+version = "0.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fb4a30d54f7443bf3d6191dcd486aca19e67cb3c49fa7a06a319966346707e7f"
+dependencies = [
+ "cipher 0.2.5",
+]
+
 [[package]]
 name = "cxx"
 version = "1.0.94"
@@ -1247,6 +1498,20 @@ dependencies = [
  "synstructure 0.12.6",
 ]
 
+[[package]]
+name = "deadpool"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3d126179d86aee4556e54f5f3c6bf6d9884e7cc52cef82f77ee6f90a7747616d"
+dependencies = [
+ "async-trait",
+ "config",
+ "crossbeam-queue",
+ "num_cpus",
+ "serde",
+ "tokio",
+]
+
 [[package]]
 name = "deduplicating_array"
 version = "0.1.4"
@@ -1267,13 +1532,22 @@ dependencies = [
  "syn 1.0.109",
 ]
 
+[[package]]
+name = "digest"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d3dd60d1080a57a05ab032377049e0591415d2b31afd7028356dbf3cc6dcb066"
+dependencies = [
+ "generic-array",
+]
+
 [[package]]
 name = "digest"
 version = "0.10.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8168378f4e5023e7218c89c891c0fd8ecdb5e5e4f18cb78f38cf245dd021e76f"
 dependencies = [
- "block-buffer",
+ "block-buffer 0.10.4",
  "crypto-common",
  "subtle",
 ]
@@ -1589,6 +1863,21 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "futures"
+version = "0.3.28"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "23342abe12aba583913b2e62f22225ff9c950774065e4bfb61a19cd9770fec40"
+dependencies = [
+ "futures-channel",
+ "futures-core",
+ "futures-executor",
+ "futures-io",
+ "futures-sink",
+ "futures-task",
+ "futures-util",
+]
+
 [[package]]
 name = "futures-channel"
 version = "0.3.28"
@@ -1596,6 +1885,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "955518d47e09b25bbebc7a18df10b81f0c766eaf4c4f1cccef2fca5f2a4fb5f2"
 dependencies = [
  "futures-core",
+ "futures-sink",
 ]
 
 [[package]]
@@ -1604,6 +1894,17 @@ version = "0.3.28"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4bca583b7e26f571124fe5b7561d49cb2868d79116cfa0eefce955557c6fee8c"
 
+[[package]]
+name = "futures-executor"
+version = "0.3.28"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ccecee823288125bd88b4d7f565c9e58e41858e47ab72e8ea2d64e93624386e0"
+dependencies = [
+ "futures-core",
+ "futures-task",
+ "futures-util",
+]
+
 [[package]]
 name = "futures-io"
 version = "0.3.28"
@@ -1654,9 +1955,11 @@ version = "0.3.28"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "26b01e40b772d54cf6c6d721c1d1abd0647a0106a12ecaa1c186273392a69533"
 dependencies = [
+ "futures-channel",
  "futures-core",
  "futures-io",
  "futures-macro",
+ "futures-sink",
  "futures-task",
  "memchr",
  "pin-project-lite",
@@ -1692,6 +1995,17 @@ dependencies = [
  "version_check",
 ]
 
+[[package]]
+name = "getrandom"
+version = "0.1.16"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8fc3cb4d91f53b50155bdcfd23f6a4c39ae1969c2ae85982b135750cccaf5fce"
+dependencies = [
+ "cfg-if 1.0.0",
+ "libc",
+ "wasi 0.9.0+wasi-snapshot-preview1",
+]
+
 [[package]]
 name = "getrandom"
 version = "0.2.9"
@@ -1705,6 +2019,16 @@ dependencies = [
  "wasm-bindgen",
 ]
 
+[[package]]
+name = "ghash"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "97304e4cd182c3846f7575ced3890c53012ce534ad9114046b0a9e00bb30a375"
+dependencies = [
+ "opaque-debug",
+ "polyval",
+]
+
 [[package]]
 name = "gimli"
 version = "0.26.2"
@@ -1728,6 +2052,18 @@ version = "0.3.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d2fabcfbdc87f4758337ca535fb41a6d701b65693ce38287d856d1674551ec9b"
 
+[[package]]
+name = "gloo-timers"
+version = "0.2.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9b995a66bb87bebce9a0f4a95aed01daca4872c050bfcb21653361c03bc35e5c"
+dependencies = [
+ "futures-channel",
+ "futures-core",
+ "js-sys",
+ "wasm-bindgen",
+]
+
 [[package]]
 name = "h2"
 version = "0.3.18"
@@ -1816,13 +2152,33 @@ version = "0.3.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fed44880c466736ef9a5c5b5facefb5ed0785676d0c02d612db14e54f0d84286"
 
+[[package]]
+name = "hkdf"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "51ab2f639c231793c5f6114bdb9bbe50a7dbbfcd7c7c6bd8475dec2d991e964f"
+dependencies = [
+ "digest 0.9.0",
+ "hmac 0.10.1",
+]
+
+[[package]]
+name = "hmac"
+version = "0.10.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c1441c6b1e930e2817404b5046f1f989899143a12bf92de603b69f4e0aee1e15"
+dependencies = [
+ "crypto-mac",
+ "digest 0.9.0",
+]
+
 [[package]]
 name = "hmac"
 version = "0.12.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6c49c37c09c17a53d937dfbb742eb3a961d65a994e6bcdcf37e7399d0cc8ab5e"
 dependencies = [
- "digest",
+ "digest 0.10.6",
 ]
 
 [[package]]
@@ -1847,6 +2203,47 @@ dependencies = [
  "pin-project-lite",
 ]
 
+[[package]]
+name = "http-client"
+version = "6.5.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1947510dc91e2bf586ea5ffb412caad7673264e14bb39fb9078da114a94ce1a5"
+dependencies = [
+ "async-h1",
+ "async-std",
+ "async-tls",
+ "async-trait",
+ "cfg-if 1.0.0",
+ "dashmap",
+ "deadpool",
+ "futures",
+ "http-types",
+ "log",
+ "rustls",
+]
+
+[[package]]
+name = "http-types"
+version = "2.12.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6e9b187a72d63adbfba487f48095306ac823049cb504ee195541e91c7775f5ad"
+dependencies = [
+ "anyhow",
+ "async-channel",
+ "async-std",
+ "base64 0.13.1",
+ "cookie",
+ "futures-lite",
+ "infer",
+ "pin-project-lite",
+ "rand 0.7.3",
+ "serde",
+ "serde_json",
+ "serde_qs",
+ "serde_urlencoded",
+ "url",
+]
+
 [[package]]
 name = "httparse"
 version = "1.8.0"
@@ -2401,6 +2798,12 @@ version = "2.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9f2cb48b81b1dc9f39676bf99f5499babfec7cd8fe14307f7b3d747208fb5690"
 
+[[package]]
+name = "infer"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "64e9829a50b42bb782c1df523f78d332fe371b10c661e78b7a3c34b0198e9fac"
+
 [[package]]
 name = "instant"
 version = "0.1.12"
@@ -2492,6 +2895,15 @@ dependencies = [
  "wasm-bindgen",
 ]
 
+[[package]]
+name = "kv-log-macro"
+version = "1.0.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0de8b303297635ad57c9f5059fd9cee7a47f8e8daa09df0fcd07dd39fb22977f"
+dependencies = [
+ "log",
+]
+
 [[package]]
 name = "lazy_static"
 version = "1.4.0"
@@ -2504,6 +2916,19 @@ version = "0.2.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "884e2677b40cc8c339eaefcb701c32ef1fd2493d71118dc0ca4b6a736c93bd67"
 
+[[package]]
+name = "lexical-core"
+version = "0.7.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6607c62aa161d23d17a9072cc5da0be67cdfc89d3afb1e8d9c842bebc2525ffe"
+dependencies = [
+ "arrayvec",
+ "bitflags 1.3.2",
+ "cfg-if 1.0.0",
+ "ryu",
+ "static_assertions",
+]
+
 [[package]]
 name = "libc"
 version = "0.2.142"
@@ -2565,6 +2990,9 @@ name = "log"
 version = "0.4.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "518ef76f2f87365916b142844c16d8fefd85039bc5699050210a7778ee1cd1de"
+dependencies = [
+ "value-bag",
+]
 
 [[package]]
 name = "loupe"
@@ -2667,6 +3095,16 @@ version = "0.3.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6877bb514081ee2a7ff5ef9de3281f14a4dd4bceac4c09388074a6b5df8a139a"
 
+[[package]]
+name = "mime_guess"
+version = "2.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4192263c238a5f0d0c6bfd21f336a313a4ce1c450542449ca191bb657b4642ef"
+dependencies = [
+ "mime",
+ "unicase",
+]
+
 [[package]]
 name = "miniz_oxide"
 version = "0.6.2"
@@ -2746,6 +3184,17 @@ dependencies = [
  "static_assertions",
 ]
 
+[[package]]
+name = "nom"
+version = "5.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "08959a387a676302eebf4ddbcbc611da04285579f76f88ee0506c63b1a61dd4b"
+dependencies = [
+ "lexical-core",
+ "memchr",
+ "version_check",
+]
+
 [[package]]
 name = "num-bigint"
 version = "0.4.3"
@@ -2994,7 +3443,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7676374caaee8a325c9e7a2ae557f216c5563a171d6997b0ef8a65af35147700"
 dependencies = [
  "base64ct",
- "rand_core",
+ "rand_core 0.6.4",
  "subtle",
 ]
 
@@ -3004,10 +3453,10 @@ version = "0.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "83a0692ec44e4cf1ef28ca317f14f8f07da2d95ec3fa01f86e4467b725e60917"
 dependencies = [
- "digest",
- "hmac",
+ "digest 0.10.6",
+ "hmac 0.12.1",
  "password-hash",
- "sha2",
+ "sha2 0.10.6",
 ]
 
 [[package]]
@@ -3042,7 +3491,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b1181c94580fa345f50f19d738aaa39c0ed30a600d95cb2d3e23f94266f14fbf"
 dependencies = [
  "phf_shared",
- "rand",
+ "rand 0.8.5",
 ]
 
 [[package]]
@@ -3067,6 +3516,26 @@ dependencies = [
  "siphasher",
 ]
 
+[[package]]
+name = "pin-project"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c95a7476719eab1e366eaf73d0260af3021184f18177925b07f54b30089ceead"
+dependencies = [
+ "pin-project-internal",
+]
+
+[[package]]
+name = "pin-project-internal"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "39407670928234ebc5e6e580247dd567ad73a3578460c5990f9503df207e8f07"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.18",
+]
+
 [[package]]
 name = "pin-project-lite"
 version = "0.2.9"
@@ -3135,6 +3604,17 @@ version = "0.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "22686f4785f02a4fcc856d3b3bb19bf6c8160d103f7a99cc258bddd0251dc7f2"
 
+[[package]]
+name = "polyval"
+version = "0.4.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "eebcc4aa140b9abd2bc40d9c3f7ccec842679cd79045ac3a7ac698c1a064b7cd"
+dependencies = [
+ "cpuid-bool",
+ "opaque-debug",
+ "universal-hash",
+]
+
 [[package]]
 name = "postcard"
 version = "1.0.4"
@@ -3239,6 +3719,19 @@ dependencies = [
  "nibble_vec",
 ]
 
+[[package]]
+name = "rand"
+version = "0.7.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6a6b1679d49b24bbfe0c803429aa1874472f50d9b363131f0e89fc356b544d03"
+dependencies = [
+ "getrandom 0.1.16",
+ "libc",
+ "rand_chacha 0.2.2",
+ "rand_core 0.5.1",
+ "rand_hc",
+]
+
 [[package]]
 name = "rand"
 version = "0.8.5"
@@ -3246,8 +3739,18 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "34af8d1a0e25924bc5b7c43c079c942339d8f0a8b57c39049bef581b46327404"
 dependencies = [
  "libc",
- "rand_chacha",
- "rand_core",
+ "rand_chacha 0.3.1",
+ "rand_core 0.6.4",
+]
+
+[[package]]
+name = "rand_chacha"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f4c8ed856279c9737206bf725bf36935d8666ead7aa69b52be55af369d193402"
+dependencies = [
+ "ppv-lite86",
+ "rand_core 0.5.1",
 ]
 
 [[package]]
@@ -3257,7 +3760,16 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e6c10a63a0fa32252be49d21e7709d4d4baf8d231c2dbce1eaa8141b9b127d88"
 dependencies = [
  "ppv-lite86",
- "rand_core",
+ "rand_core 0.6.4",
+]
+
+[[package]]
+name = "rand_core"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "90bde5296fc891b0cef12a6d03ddccc162ce7b2aff54160af9338f8d40df6d19"
+dependencies = [
+ "getrandom 0.1.16",
 ]
 
 [[package]]
@@ -3266,7 +3778,16 @@ version = "0.6.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ec0be4795e2f6a28069bec0b5ff3e2ac9bafc99e6a9a7dc3547996c5c816922c"
 dependencies = [
- "getrandom",
+ "getrandom 0.2.9",
+]
+
+[[package]]
+name = "rand_hc"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ca3129af7b92a17112d59ad498c6f81eaf463253766b90396d39ea7a39d6613c"
+dependencies = [
+ "rand_core 0.5.1",
 ]
 
 [[package]]
@@ -3321,7 +3842,7 @@ version = "0.4.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b033d837a7cf162d7993aded9304e30a83213c648b6e389db233191f891e5c2b"
 dependencies = [
- "getrandom",
+ "getrandom 0.2.9",
  "redox_syscall 0.2.16",
  "thiserror",
 ]
@@ -3396,7 +3917,7 @@ version = "0.11.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "27b71749df584b7f4cac2c426c127a7c785a5106cc98f7a8feb044115f0fa254"
 dependencies = [
- "base64",
+ "base64 0.21.0",
  "bytes",
  "encoding_rs",
  "futures-core",
@@ -3427,6 +3948,21 @@ dependencies = [
  "winreg",
 ]
 
+[[package]]
+name = "ring"
+version = "0.16.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3053cf52e236a3ed746dfc745aa9cacf1b791d846bdaf412f60a8d7d6e17c8fc"
+dependencies = [
+ "cc",
+ "libc",
+ "once_cell",
+ "spin",
+ "untrusted",
+ "web-sys",
+ "winapi",
+]
+
 [[package]]
 name = "rkyv"
 version = "0.7.41"
@@ -3487,6 +4023,19 @@ dependencies = [
  "windows-sys 0.48.0",
 ]
 
+[[package]]
+name = "rustls"
+version = "0.18.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5d1126dcf58e93cee7d098dbda643b5f92ed724f1f6a63007c1116eed6700c81"
+dependencies = [
+ "base64 0.12.3",
+ "log",
+ "ring",
+ "sct",
+ "webpki",
+]
+
 [[package]]
 name = "rustversion"
 version = "1.0.12"
@@ -3570,6 +4119,16 @@ version = "1.0.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1792db035ce95be60c3f8853017b3999209281c24e2ba5bc8e59bf97a0c590c1"
 
+[[package]]
+name = "sct"
+version = "0.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b362b83898e0e69f38515b82ee15aa80636befe47c3b6d3d89a911e78fc228ce"
+dependencies = [
+ "ring",
+ "untrusted",
+]
+
 [[package]]
 name = "seahash"
 version = "4.1.0"
@@ -3674,6 +4233,17 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "serde_qs"
+version = "0.8.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c7715380eec75f029a4ef7de39a9200e0a63823176b759d055b613f5a87df6a6"
+dependencies = [
+ "percent-encoding",
+ "serde",
+ "thiserror",
+]
+
 [[package]]
 name = "serde_repr"
 version = "0.1.12"
@@ -3736,7 +4306,7 @@ checksum = "f04293dc80c3993519f2d7f6f511707ee7094fe0c6d3406feb330cdb3540eba3"
 dependencies = [
  "cfg-if 1.0.0",
  "cpufeatures",
- "digest",
+ "digest 0.10.6",
 ]
 
 [[package]]
@@ -3745,6 +4315,19 @@ version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ae1a47186c03a32177042e55dbc5fd5aee900b8e0069a8d70fba96a9375cd012"
 
+[[package]]
+name = "sha2"
+version = "0.9.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4d58a1e1bf39749807d89cf2d98ac2dfa0ff1cb3faa38fbb64dd88ac8013d800"
+dependencies = [
+ "block-buffer 0.9.0",
+ "cfg-if 1.0.0",
+ "cpufeatures",
+ "digest 0.9.0",
+ "opaque-debug",
+]
+
 [[package]]
 name = "sha2"
 version = "0.10.6"
@@ -3753,7 +4336,7 @@ checksum = "82e6b795fe2e3b1e845bafcb27aa35405c4d47cdfc92af5fc8d3002f76cebdc0"
 dependencies = [
  "cfg-if 1.0.0",
  "cpufeatures",
- "digest",
+ "digest 0.10.6",
 ]
 
 [[package]]
@@ -3801,6 +4384,15 @@ version = "0.1.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f27f6278552951f1f2b8cf9da965d10969b2efdea95a6ec47987ab46edfe263a"
 
+[[package]]
+name = "simple-mutex"
+version = "1.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "38aabbeafa6f6dead8cebf246fe9fae1f9215c8d29b3a69f93bd62a9e4a3dcd6"
+dependencies = [
+ "event-listener",
+]
+
 [[package]]
 name = "simple_logger"
 version = "4.1.0"
@@ -3871,6 +4463,12 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "spin"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6e63cff320ae2c57904679ba7cb63280a3dc4613885beafb148ee7bf9aa9042d"
+
 [[package]]
 name = "sptr"
 version = "0.3.2"
@@ -3984,6 +4582,28 @@ version = "2.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6bdef32e8150c2a081110b42772ffe7d7c9032b606bc226c8260fd97e0976601"
 
+[[package]]
+name = "surf"
+version = "2.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "718b1ae6b50351982dedff021db0def601677f2120938b070eadb10ba4038dd7"
+dependencies = [
+ "async-std",
+ "async-trait",
+ "cfg-if 1.0.0",
+ "futures-util",
+ "getrandom 0.2.9",
+ "http-client",
+ "http-types",
+ "log",
+ "mime_guess",
+ "once_cell",
+ "pin-project-lite",
+ "rustls",
+ "serde",
+ "serde_json",
+]
+
 [[package]]
 name = "syn"
 version = "1.0.109"
@@ -4418,6 +5038,15 @@ version = "1.16.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "497961ef93d974e23eb6f433eb5fe1b7930b659f06d12dec6fc44a8f554c0bba"
 
+[[package]]
+name = "unicase"
+version = "2.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "50f37be617794602aabbeee0be4f259dc1778fabe05e2d67ee8f79326d5cb4f6"
+dependencies = [
+ "version_check",
+]
+
 [[package]]
 name = "unicode-bidi"
 version = "0.3.13"
@@ -4473,12 +5102,28 @@ version = "0.2.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f962df74c8c05a667b5ee8bcf162993134c104e96440b663c8daa176dc772d8c"
 
+[[package]]
+name = "universal-hash"
+version = "0.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9f214e8f697e925001e66ec2c6e37a4ef93f0f78c2eed7814394e10c62025b05"
+dependencies = [
+ "generic-array",
+ "subtle",
+]
+
 [[package]]
 name = "unsafe-libyaml"
 version = "0.2.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1865806a559042e51ab5414598446a5871b561d21b6764f2eabb0dd481d880a6"
 
+[[package]]
+name = "untrusted"
+version = "0.7.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a156c684c91ea7d62626509bce3cb4e1d9ed5c4d978f7b4352658f96a4c26b4a"
+
 [[package]]
 name = "url"
 version = "2.3.1"
@@ -4488,6 +5133,7 @@ dependencies = [
  "form_urlencoded",
  "idna",
  "percent-encoding",
+ "serde",
 ]
 
 [[package]]
@@ -4514,6 +5160,12 @@ version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "830b7e5d4d90034032940e4ace0d9a9a057e7a45cd94e6c007832e39edb82f6d"
 
+[[package]]
+name = "value-bag"
+version = "1.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a4d330786735ea358f3bc09eea4caa098569c1c93f342d9aca0514915022fe7e"
+
 [[package]]
 name = "vcpkg"
 version = "0.2.15"
@@ -4552,6 +5204,12 @@ dependencies = [
  "try-lock",
 ]
 
+[[package]]
+name = "wasi"
+version = "0.9.0+wasi-snapshot-preview1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cccddf32554fecc6acb585f82a32a72e28b48f8c4c1883ddfeeeaa96f7d8e519"
+
 [[package]]
 name = "wasi"
 version = "0.10.0+wasi-snapshot-preview1"
@@ -4878,7 +5536,7 @@ checksum = "fadbe31e3c1b6f3e398ad172b169152ae1a743ae6efd5f9ffb34019983319d99"
 dependencies = [
  "cfg-if 1.0.0",
  "generational-arena",
- "getrandom",
+ "getrandom 0.2.9",
  "libc",
  "thiserror",
  "tracing",
@@ -4916,6 +5574,25 @@ dependencies = [
  "wasm-bindgen",
 ]
 
+[[package]]
+name = "webpki"
+version = "0.21.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b8e38c0608262c46d4a56202ebabdeb094cef7e560ca7a226c6bf055188aa4ea"
+dependencies = [
+ "ring",
+ "untrusted",
+]
+
+[[package]]
+name = "webpki-roots"
+version = "0.20.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0f20dea7535251981a9670857150d571846545088359b28e4951d350bdaf179f"
+dependencies = [
+ "webpki",
+]
+
 [[package]]
 name = "which"
 version = "4.4.0"
@@ -5272,14 +5949,14 @@ version = "0.6.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0445d0fbc924bb93539b4316c11afb121ea39296f99a3c4c9edad09e3658cdef"
 dependencies = [
- "aes",
+ "aes 0.7.5",
  "byteorder",
  "bzip2",
  "constant_time_eq",
  "crc32fast",
  "crossbeam-utils",
  "flate2",
- "hmac",
+ "hmac 0.12.1",
  "pbkdf2",
  "sha1 0.10.5",
  "time 0.3.20",
diff --git a/boa_examples/Cargo.toml b/boa_examples/Cargo.toml
index fde260b8c0a..c3f9814f388 100644
--- a/boa_examples/Cargo.toml
+++ b/boa_examples/Cargo.toml
@@ -18,3 +18,6 @@ boa_parser.workspace = true
 boa_runtime.workspace = true
 smol = "1.3.0"
 futures-util = "0.3.28"
+surf = { version = "2.3.2", default-features = false, features = [
+    "h1-client-rustls",
+] }
diff --git a/boa_examples/src/bin/module_fetch.rs b/boa_examples/src/bin/module_fetch.rs
new file mode 100644
index 00000000000..1c081874f9b
--- /dev/null
+++ b/boa_examples/src/bin/module_fetch.rs
@@ -0,0 +1,249 @@
+use std::{
+    cell::{Cell, RefCell},
+    collections::VecDeque,
+    rc::Rc,
+};
+
+use boa_engine::{
+    builtins::promise::PromiseState,
+    job::{FutureJob, JobQueue, NativeJob},
+    module::ModuleLoader,
+    string::utf16,
+    Context, JsNativeError, JsResult, JsString, JsValue, Module,
+};
+use boa_parser::Source;
+use futures_util::{stream::FuturesUnordered, StreamExt};
+use smol::{future, LocalExecutor};
+use surf::{middleware::Redirect, Client};
+
+// Most of the boilerplate is taken from the `futures.rs` example.
+// This file only explains what is exclusive of async module loading.
+
+#[derive(Debug, Default)]
+struct HttpModuleLoader;
+
+impl ModuleLoader for HttpModuleLoader {
+    fn load_imported_module(
+        &self,
+        _referrer: boa_engine::module::Referrer,
+        specifier: JsString,
+        finish_load: Box<dyn FnOnce(boa_engine::JsResult<Module>, &mut Context<'_>)>,
+        context: &mut Context<'_>,
+    ) {
+        let url = specifier.to_std_string_escaped();
+
+        let fetch = async move {
+            // `surf` requires to manually specify following redirects.
+            let client = Client::default().with(Redirect::default());
+
+            // Adding some prints to show the non-deterministic nature of the async fetches.
+            // Try to run the example several times to see how sometimes the fetches start in order
+            // but finish in disorder.
+            println!("Fetching `{url}`...");
+            // This could also retry fetching in case there's an error while requesting the module.
+            let body = client.get(&url).recv_string().await;
+            println!("Finished fetching `{url}`!");
+
+            // Since the async context cannot take the `context` by ref, we have to continue
+            // parsing inside a new `NativeJob` that will be enqueued into the promise job queue.
+            NativeJob::new(move |context| -> JsResult<JsValue> {
+                let body = match body {
+                    Ok(body) => body,
+                    Err(err) => {
+                        // On error we always call `finish_load` to notify the load promise about the
+                        // error.
+                        finish_load(
+                            Err(JsNativeError::typ().with_message(err.to_string()).into()),
+                            context,
+                        );
+
+                        // Just returns anything to comply with `NativeJob::new`'s signature.
+                        return Ok(JsValue::undefined());
+                    }
+                };
+
+                // Could also add a path if needed.
+                let source = Source::from_bytes(body.as_bytes());
+
+                let module = Module::parse(source, None, context);
+
+                // We don't do any error handling, `finish_load` takes care of that for us.
+                finish_load(module, context);
+
+                // Also needed to match `NativeJob::new`.
+                Ok(JsValue::undefined())
+            })
+        };
+
+        // Just enqueue the future for now. We'll advance all the enqueued futures inside our custom
+        // `JobQueue`.
+        context
+            .job_queue()
+            .enqueue_future_job(Box::pin(fetch), context)
+    }
+}
+
+fn main() {
+    // A simple snippet that imports modules from the web instead of the file system.
+    const SRC: &str = r#"
+        import YAML from 'https://esm.run/yaml';
+        import fromAsync from 'https://esm.run/array-from-async';
+        import { Base64 } from 'https://esm.run/js-base64';
+
+        const data = `
+            object:
+                array: ["hello", "world"]
+                key: "value"
+        `;
+
+        const object = YAML.parse(data).object;
+
+        let result = await fromAsync([
+            Promise.resolve(Base64.encode(object.array[0])),
+            Promise.resolve(Base64.encode(object.array[1])),
+        ]);
+
+        export default result;
+    "#;
+
+    let executor = LocalExecutor::new();
+    let loader: &dyn ModuleLoader = &HttpModuleLoader;
+    let queue: Rc<dyn JobQueue> = Rc::new(Queue::new(executor));
+    let context = &mut Context::builder()
+        .job_queue(queue)
+        // NEW: sets the context module loader to our custom loader
+        .module_loader(loader)
+        .build()
+        .unwrap();
+
+    let module = Module::parse(Source::from_bytes(SRC.as_bytes()), None, context).unwrap();
+
+    // Calling `Module::load_link_evaluate` takes care of having to define promise handlers for
+    // `Module::load` and `Module::evaluate`.
+    let promise = module.load_link_evaluate(context).unwrap();
+
+    // Important to call `Context::run_jobs`, or else all the futures and promises won't be
+    // pushed forward by the job queue.
+    context.run_jobs();
+
+    match promise.state().unwrap() {
+        // Our job queue guarantees that all promises and futures are finished after returning
+        // from `Context::run_jobs`.
+        // Some other job queue designs only execute a "microtick" or a single pass through the
+        // pending promises and futures. In that case, you can pass this logic as a promise handler
+        // for `promise` instead.
+        PromiseState::Pending => panic!("module didn't execute!"),
+        // All modules after successfully evaluating return `JsValue::undefined()`.
+        PromiseState::Fulfilled(v) => {
+            assert_eq!(v, JsValue::undefined())
+        }
+        PromiseState::Rejected(err) => {
+            panic!("{}", err.display());
+        }
+    }
+
+    let default = module.namespace(context).get("default", context).unwrap();
+    // `default` should contain the result of our calculations.
+    let default = default.as_object().unwrap();
+
+    assert_eq!(
+        default.get(0, context).unwrap().as_string().unwrap(),
+        utf16!("aGVsbG8=")
+    );
+    assert_eq!(
+        default.get(1, context).unwrap().as_string().unwrap(),
+        utf16!("d29ybGQ=")
+    );
+}
+
+// Taken from the `futures.rs` example.
+struct Queue<'a> {
+    executor: LocalExecutor<'a>,
+    futures: RefCell<FuturesUnordered<FutureJob>>,
+    jobs: RefCell<VecDeque<NativeJob>>,
+}
+
+impl<'a> Queue<'a> {
+    fn new(executor: LocalExecutor<'a>) -> Self {
+        Self {
+            executor,
+            futures: RefCell::default(),
+            jobs: RefCell::default(),
+        }
+    }
+}
+
+impl<'a> JobQueue for Queue<'a> {
+    fn enqueue_promise_job(&self, job: NativeJob, _context: &mut boa_engine::Context<'_>) {
+        self.jobs.borrow_mut().push_back(job);
+    }
+
+    fn enqueue_future_job(&self, future: FutureJob, _context: &mut boa_engine::Context<'_>) {
+        self.futures.borrow().push(future)
+    }
+
+    fn run_jobs(&self, context: &mut boa_engine::Context<'_>) {
+        // Early return in case there were no jobs scheduled.
+        if self.jobs.borrow().is_empty() && self.futures.borrow().is_empty() {
+            return;
+        }
+
+        let context = RefCell::new(context);
+
+        future::block_on(self.executor.run(async move {
+            // Used to sync the finalization of both tasks
+            let finished = Cell::new(0b00u8);
+
+            let fqueue = async {
+                loop {
+                    if self.futures.borrow().is_empty() {
+                        finished.set(finished.get() | 0b01);
+                        if finished.get() >= 0b11 {
+                            // All possible futures and jobs were completed. Exit.
+                            return;
+                        }
+                        // All possible jobs were completed, but `jqueue` could have
+                        // pending jobs. Yield to the executor to try to progress on
+                        // `jqueue` until we have more pending futures.
+                        future::yield_now().await;
+                        continue;
+                    }
+                    finished.set(finished.get() & 0b10);
+
+                    let futures = &mut std::mem::take(&mut *self.futures.borrow_mut());
+                    while let Some(job) = futures.next().await {
+                        self.enqueue_promise_job(job, &mut context.borrow_mut());
+                    }
+                }
+            };
+
+            let jqueue = async {
+                loop {
+                    if self.jobs.borrow().is_empty() {
+                        finished.set(finished.get() | 0b10);
+                        if finished.get() >= 0b11 {
+                            // All possible futures and jobs were completed. Exit.
+                            return;
+                        }
+                        // All possible jobs were completed, but `fqueue` could have
+                        // pending futures. Yield to the executor to try to progress on
+                        // `fqueue` until we have more pending jobs.
+                        future::yield_now().await;
+                        continue;
+                    };
+                    finished.set(finished.get() & 0b01);
+
+                    let jobs = std::mem::take(&mut *self.jobs.borrow_mut());
+                    for job in jobs {
+                        if let Err(e) = job.call(&mut context.borrow_mut()) {
+                            eprintln!("Uncaught {e}");
+                        }
+                        future::yield_now().await;
+                    }
+                }
+            };
+
+            future::zip(fqueue, jqueue).await;
+        }))
+    }
+}