refactor(web/tvixbolt): buildRustPackage -> crate2nix

With the recent changes to crate2nix and buildRustCrate in nixpkgs it is
now possible to build tvixbolt via crate2nix like we do for other tvix
crates. We can reuse a lot of the customizations done in //tvix in
tvixbolt to avoid repeating ourselves.

A script for serving tvixbolt locally for testing purposes is also
available now through the .serve attribute of tvixbolt.

This change supersedes https://cl.tvl.fyi/c/depot/+/11821.

Change-Id: I4864df8b75aec73cf5fee2428924ed4cfbb32902
Reviewed-on: https://cl.tvl.fyi/c/depot/+/11952
Tested-by: BuildkiteCI
Autosubmit: Ilan Joselevich <personal@ilanjoselevich.com>
Reviewed-by: flokli <flokli@flokli.de>

tvix/docs/src/TODO.md

@@ -25,18 +25,6 @@ sure noone is working on this, or has some specific design in mind already.
    with a different level of `--strict`, but the toplevel doc-comment suggests
    its generic?
 
-### crate2nix for WASM (@kranzes)
-Most of Tvix is living inside a `//tvix` cargo workspace, and we use `crate2nix`
-as a build system, to get crate-level build granularity (and caching), keeping
-compile times somewhat manageable.
-
-Thanks to the recent crate2nix fixes, we can now use it to build WASM.
-We should migrate `//web/tvixbolt` from `rustPlatform.buildRustPackage` to
-`crate2nix`.
-An initial cl/11821 to move it to the `//tvix` workspace got some pushback, we
-should see if it's possible to keep it in a separate directory and still refer
-to the (cleaned) sources described in `tvix/default.nix`.
-
 ## Perf
  - String Contexts currently do a lot of indirections (edef)
    (NixString -> NixStringInner -> HashSet[element] -> NixContextElement -> String -> data)

web/tvixbolt/Cargo.lock

@@ -412,9 +412,9 @@ checksum = "b1a46d1a171d865aa5f83f92695765caa047a9b4cbae2cbf37dbd613a793fd4c"
 
 [[package]]
 name = "js-sys"
-version = "0.3.66"
+version = "0.3.69"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cee9c64da59eae3b50095c18d3e74f8b73c0b86d2792824ff01bbce68ba229ca"
+checksum = "29c15563dc2726973df627357ce0c9ddddbea194836909d655df6a75d2cf296d"
 dependencies = [
  "wasm-bindgen",
 ]
@@ -727,9 +727,9 @@ checksum = "3ddc765d3410d9f6c6ca071bf0b67f6b01e3ec4595dc3892f02677e75819dddc"
 
 [[package]]
 name = "serde"
-version = "1.0.195"
+version = "1.0.203"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "63261df402c67811e9ac6def069e4786148c4563f4b50fd4bf30aa370d626b02"
+checksum = "7253ab4de971e72fb7be983802300c30b5a7f0c2e56fab8abfc6a214307c0094"
 dependencies = [
  "serde_derive",
 ]
@@ -748,9 +748,9 @@ dependencies = [
 
 [[package]]
 name = "serde_derive"
-version = "1.0.195"
+version = "1.0.203"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "46fe8f8603d81ba86327b23a2e9cdf49e1255fb94a4c5f297f6ee0547178ea2c"
+checksum = "500cbc0ebeb6f46627f50f3f5811ccf6bf00643be300b4c3eabc0ef55dc5b5ba"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -979,10 +979,7 @@ dependencies = [
 name = "tvixbolt"
 version = "0.1.0"
 dependencies = [
- "codemap",
- "rnix",
  "serde",
- "serde_urlencoded",
  "tvix-eval",
  "wasm-bindgen",
  "web-sys",
@@ -1088,9 +1085,9 @@ checksum = "af190c94f2773fdb3729c55b007a722abb5384da03bc0986df4c289bf5567e96"
 
 [[package]]
 name = "web-sys"
-version = "0.3.66"
+version = "0.3.69"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "50c24a44ec86bb68fbecd1b3efed7e85ea5621b39b35ef2766b66cd984f8010f"
+checksum = "77afa9a11836342370f4817622a2f0f418b134426d91a82dfb48f532d2ec13ef"
 dependencies = [
  "js-sys",
  "wasm-bindgen",

web/tvixbolt/Cargo.toml

@@ -3,24 +3,13 @@ name = "tvixbolt"
 version = "0.1.0"
 edition = "2021"
 
+[lib]
+crate-type = ["cdylib"]
+
 [dependencies]
 yew = "0.19.3"
 yew-router = "0.16"
-codemap = "0.1.3"
+tvix-eval = { path = "../../tvix/eval", default-features = false }
-serde_urlencoded = "*" # pinned by yew
+serde = { version = "1.0.203", features = ["derive"] }
-rnix = "0.11.0"
+web-sys = { version = "0.3.69", features = ["HtmlDetailsElement"] }
-
+wasm-bindgen = "0.2.92"
-# needs to be in sync with nixpkgs
-wasm-bindgen = "= 0.2.92"
-
-[dependencies.tvix-eval]
-path = "../../tvix/eval"
-default-features = false
-
-[dependencies.serde]
-version = "*" # pinned by yew
-features = [ "derive" ]
-
-[dependencies.web-sys]
-version = "*" # pinned by yew
-features = [ "HtmlDetailsElement" ]

web/tvixbolt/default.nix

@@ -1,74 +1,30 @@
-{ depot, lib, pkgs, ... }:
+{ pkgs, lib, depot, ... }:
-
 let
-  wasmRust = pkgs.rust-bin.stable.latest.default.override {
+  pkgsCross = pkgs.pkgsCross.wasm32-unknown-none;
-    targets = [ "wasm32-unknown-unknown" ];
-  };
-
-  cargoToml = with builtins; fromTOML (readFile ./Cargo.toml);
-
-  wasmBindgenMatch =
-    cargoToml.dependencies.wasm-bindgen == "= ${pkgs.wasm-bindgen-cli.version}";
-
-  assertWasmBindgen = assert (lib.assertMsg wasmBindgenMatch ''
-    Due to instability in the Rust WASM ecosystem, the trunk build
-    tool enforces that the Cargo-dependency version of `wasm-bindgen`
-    MUST match the version of the CLI supplied in the environment.
-
-    This can get out of sync when nixpkgs is updated. To resolve it,
-    wasm-bindgen must be bumped in the Cargo.toml file and cargo needs
-    to be run to resolve the dependencies.
-
-    Versions of `wasm-bindgen` in Cargo.toml:
-
-      Expected: '= ${pkgs.wasm-bindgen-cli.version}'
-      Actual:   '${cargoToml.dependencies.wasm-bindgen}'
-  ''); pkgs.wasm-bindgen-cli;
-
-  deps = [
-    pkgs.binaryen
-    pkgs.sass
-    pkgs.trunk
-
-    wasmRust
-    assertWasmBindgen
-  ];
-
-  # Cargo.toml needs to be patched with the /nix/store source path of
-  # tvix-eval.
-  cargoTomlPatch = pkgs.writeText "tvix-eval-src.patch" ''
-    diff --git a/Cargo.toml b/Cargo.toml
-    index 75006bec18..6ca244bbb2 100644
-    --- a/Cargo.toml
-    +++ b/Cargo.toml
-    @@ -16,7 +16,7 @@ rnix = "0.11.0"
-     wasm-bindgen = "= 0.2.83"
-
-     [dependencies.tvix-eval]
-    -path = "../../tvix/eval"
-    +path = "${../../tvix/eval}"
-     default-features = false
-
-     [dependencies.serde]
-  '';
 in
-pkgs.rustPlatform.buildRustPackage rec {
+(pkgsCross.callPackage ./Cargo.nix {
-  pname = "tvixbolt";
+  defaultCrateOverrides = (depot.tvix.utils.defaultCrateOverridesForPkgs pkgsCross) // {
-  version = "canon";
+    tvixbolt = prev: {
-  src = lib.cleanSource ./.;
+      src = depot.tvix.utils.filterRustCrateSrc { root = prev.src.origSrc; };
+    };
+  };
+}).rootCrate.build.overrideAttrs (oldAttrs: {
+  installPhase = ''
+    ${lib.getExe pkgs.wasm-bindgen-cli} \
+      --target web \
+      --out-dir $out \
+      --out-name ${oldAttrs.crateName} \
+      --no-typescript \
+      target/lib/${oldAttrs.crateName}-${oldAttrs.metadata}.wasm
 
-  cargoLock.lockFile = ./Cargo.lock;
+      mv src/*.{html,css} $out
-
-  patches = [
-    cargoTomlPatch
-  ];
-
-  buildPhase = ''
-    export PATH=${lib.makeBinPath deps}:$PATH
-    mkdir home
-    export HOME=$PWD/home
-    trunk build --release -d $out
   '';
 
-  dontInstall = true;
+  passthru.serve = pkgs.writeShellScriptBin "tvixbolt-serve" ''
-}
+    ${lib.getExe pkgs.simple-http-server} \
+        --index \
+        --nocache \
+        "$@" \
+        ${depot.web.tvixbolt}
+  '';
+})

web/tvixbolt/index.html

@@ -1,11 +0,0 @@
-<!DOCTYPE html>
-<html>
-  <head>
-    <meta charset="utf-8" />
-    <meta name="viewport" content="width=device-width, initial-scale=1">
-    <link rel="stylesheet"
-          href="https://static.tvl.su/latest/terminal.min.css" />
-    <link data-trunk rel="inline" href="index.css">
-    <title>Tvixbolt</title>
-  </head>
-</html>

web/tvixbolt/src/index.html

@@ -0,0 +1,21 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <meta content="text/html;charset=utf-8" http-equiv="Content-Type">
+    <meta name="viewport" content="width=device-width, initial-scale=1">
+    <link rel="stylesheet" href="https://static.tvl.su/latest/terminal.min.css">
+    <link rel="stylesheet" href="index.css">
+    <title>Tvixbolt</title>
+  </head>
+  <body>
+    <script type="module">
+      import init, { main } from './tvixbolt.js';
+
+      async function run() {
+        await init();
+	main();
+      }
+
+      run();
+    </script>
+  </body>

web/tvixbolt/src/lib.rs

@@ -7,6 +7,7 @@ use std::fmt::Write;
 
 use serde::{Deserialize, Serialize};
 use tvix_eval::observer::{DisassemblingObserver, TracingObserver};
+use wasm_bindgen::prelude::wasm_bindgen;
 use web_sys::HtmlDetailsElement;
 use web_sys::HtmlTextAreaElement;
 use yew::prelude::*;
@@ -310,6 +311,7 @@ fn eval(model: &Model) -> Output {
     out
 }
 
-fn main() {
+#[wasm_bindgen]
+pub fn main() {
     yew::start_app::<Model>();
 }