From a560d5a02ba17a8b7d238b14df56c06be581d9cf Mon Sep 17 00:00:00 2001
From: Mohammad Kermani <mkermani144@gmail.com>
Date: Mon, 3 Oct 2022 08:54:00 +0330
Subject: [PATCH] Add {set_exports} script for {ergo-lib-wasm}

When {wasm-pack} is run with browser target, it generates a {package.json}
in which there is a {module} field, but no {main}, {type} or {exports}
field is present. This causes some of the modern tools which run in Node
be unable to use the package (Vitest is an example).

Although it may seem irrational to use the browser package in Node, but
it makes sense when we want to write tests. Many test tools such as Jest
and Vitest run in Node.

Add a {set_exports} script to be run after {wasm-pack}, updating the
generated {package.json} as follows:
- Add an {exports} field to enable new Node entry resolution feature
- Add {"type": "module"} to indicate that this is an ESM module
- Remove {module}, as it's no longer needed

{wasm-pack} may fix the issue in the future or new module entry resolution
mechanisms may be introduced in the future. Until then, this script will
enable the use of the package without getting browser environment related
issues when run in Node.

Related {wasm-pack} PR:
https://github.com/rustwasm/wasm-pack/pull/1061
---
 bindings/ergo-lib-wasm/package.json           |  4 ++--
 bindings/ergo-lib-wasm/scripts/set_exports.js | 19 +++++++++++++++++++
 2 files changed, 21 insertions(+), 2 deletions(-)
 create mode 100644 bindings/ergo-lib-wasm/scripts/set_exports.js

diff --git a/bindings/ergo-lib-wasm/package.json b/bindings/ergo-lib-wasm/package.json
index 81572f24e..2aa8daccd 100644
--- a/bindings/ergo-lib-wasm/package.json
+++ b/bindings/ergo-lib-wasm/package.json
@@ -10,8 +10,8 @@
         "doc": "jsdoc -c jsdoc.json pkg/ergo_wallet_wasm.js README.md -d docs",
         "build-nodejs": "rm -rf ./pkg-nodejs && wasm-pack build --target nodejs --out-dir pkg-nodejs && cd pkg-nodejs && node ../scripts/publish_helper -nodejs",
         "build-nodejs-alpha": "rm -rf ./pkg-nodejs && wasm-pack build --target nodejs --out-dir pkg-nodejs && cd pkg-nodejs && node ../scripts/publish_helper -nodejs && npm version minor && node ../scripts/set_alpha_version -nodejs $(git rev-parse --short HEAD)",
-        "build-browser": "rm -rf ./pkg-browser && wasm-pack build --target browser --out-dir pkg-browser --features rest && cd pkg-browser && node ../scripts/publish_helper -browser",
-        "build-browser-alpha": "rm -rf ./pkg-browser && wasm-pack build --target browser --out-dir pkg-browser --features rest && cd pkg-browser && node ../scripts/publish_helper -browser && npm version minor && node ../scripts/set_alpha_version -browser $(git rev-parse --short HEAD)",
+        "build-browser": "rm -rf ./pkg-browser && wasm-pack build --target browser --out-dir pkg-browser --features rest && cd pkg-browser && node ../scripts/publish_helper -browser && node ../scripts/set_exports",
+        "build-browser-alpha": "rm -rf ./pkg-browser && wasm-pack build --target browser --out-dir pkg-browser --features rest && cd pkg-browser && node ../scripts/publish_helper -browser && node ../scripts/set_exports && npm version minor && node ../scripts/set_alpha_version -browser $(git rev-parse --short HEAD)",
         "publish-nodejs": "npm run build-nodejs &&  cd pkg-nodejs && npm publish",
         "publish-browser": "npm run build-browser && cd pkg-browser && npm publish"
     },
diff --git a/bindings/ergo-lib-wasm/scripts/set_exports.js b/bindings/ergo-lib-wasm/scripts/set_exports.js
new file mode 100644
index 000000000..9aa5b1362
--- /dev/null
+++ b/bindings/ergo-lib-wasm/scripts/set_exports.js
@@ -0,0 +1,19 @@
+const fs = require("fs");
+
+// Remove "module" from the generated (old) {package.json}
+const {
+  module: unusedModule,
+  ...oldPackageJson
+} = require(`../pkg-browser/package.json`);
+
+const newPackageJson = {
+  ...oldPackageJson,
+  type: "module",
+  exports: {
+    ".": "./ergo_lib_wasm",
+  },
+};
+
+console.log(newPackageJson);
+
+fs.writeFileSync("./package.json", JSON.stringify(newPackageJson, null, 2));