nix: add prisma-schema-wasm.dev derivation (#4600)

Make it possible to conjure a local debug build of
`@prisma/prisma-schema-wasm` npm package with `nix build
.#prisma-schema-wasm.dev` command.

Normal `nix build .#prisma-schema-wasm` still builds in release profile
by default.

This makes it easier to test local changes to DMMF end-to-end with
TypeScript client generator.

nix/prisma-schema-wasm.nix

@@ -1,4 +1,4 @@
-{ pkgs, system, self', ... }:
+{ pkgs, lib, self', ... }:
 
 let
   toolchain = pkgs.rust-bin.fromRustupToolchainFile ../prisma-schema-wasm/rust-toolchain.toml;
@@ -7,14 +7,22 @@ let
   inherit (builtins) readFile replaceStrings;
 in
 {
-  packages.prisma-schema-wasm = stdenv.mkDerivation {
-    name = "prisma-schema-wasm";
-    nativeBuildInputs = with pkgs; [ git wasm-bindgen-cli toolchain ];
-    inherit (self'.packages.prisma-engines) configurePhase src;
-
-    buildPhase = "cargo build --release --target=wasm32-unknown-unknown -p prisma-schema-build";
-    installPhase = readFile "${scriptsDir}/install.sh";
-  };
+  packages.prisma-schema-wasm = lib.makeOverridable
+    ({ profile }: stdenv.mkDerivation {
+      name = "prisma-schema-wasm";
+      nativeBuildInputs = with pkgs; [ git wasm-bindgen-cli toolchain ];
+      inherit (self'.packages.prisma-engines) configurePhase src;
+
+      buildPhase = "cargo build --profile=${profile} --target=wasm32-unknown-unknown -p prisma-schema-build";
+      installPhase = readFile "${scriptsDir}/install.sh";
+
+      WASM_BUILD_PROFILE = profile;
+
+      passthru = {
+        dev = self'.packages.prisma-schema-wasm.override { profile = "dev"; };
+      };
+    })
+    { profile = "release"; };
 
   # Takes a package version as its single argument, and produces
   # prisma-schema-wasm with the right package.json in a temporary directory,

prisma-schema-wasm/scripts/install.sh

@@ -2,6 +2,16 @@
 
 set -euo pipefail
 
+if [[ -z "${WASM_BUILD_PROFILE:-}" ]]; then
+    WASM_BUILD_PROFILE="release"
+fi
+
+if [[ $WASM_BUILD_PROFILE == "dev" ]]; then
+    TARGET_DIR="debug"
+else
+    TARGET_DIR=$WASM_BUILD_PROFILE
+fi
+
 printf '%s\n' "entering install.sh"
 
 printf '%s\n' " -> Creating out dir..."
@@ -18,4 +28,4 @@ printf '%s\n' " -> Generating node package"
 wasm-bindgen \
   --target nodejs \
   --out-dir "$out"/src \
-  target/wasm32-unknown-unknown/release/prisma_schema_build.wasm
+  "target/wasm32-unknown-unknown/$TARGET_DIR/prisma_schema_build.wasm"