Update README.md

README.md

@@ -51,29 +51,39 @@ We are the sender in the case of a normal swap, and boltz in the case of a rever
 
 There is no requirement for a database as we will not persist and data.
 
-We simply create keys, build a script, generate a single address corresponding to this key, watch the address for payment and spend the utxo by building a transaction, solving the spending conditions and broadcasting.
-We do not need to store transaction history or address indexes etc. This has to be handled by the client. 
+We simply create keys, build a script, generate a single address corresponding to this key, watch the address for
+payment and spend the utxo by building a transaction, solving the spending conditions and broadcasting.
+We do not need to store transaction history or address indexes etc. This has to be handled by the client.
 
-The client must ensure that they are rotating the keys and preimages being used. There are helper structs and methods for this.
+The client must ensure that they are rotating the keys and preimages being used. There are helper structs and methods
+for this.
 
-In the case of `normal swaps`; In the happy case, everything goes well, boltz pays our invoice and claims the on-chain funds.
-The client (us) will ONLY be required to create the swap script and spend it in case boltz cheats and we need to claim back funds onchain from the script after a timeout. 
+In the case of `normal swaps`; In the happy case, everything goes well, boltz pays our invoice and claims the on-chain
+funds.
+The client (us) will ONLY be required to create the swap script and spend it in case boltz cheats and we need to claim
+back funds onchain from the script after a timeout.
 We would be the `sender`; and can only spend after a timeout in case of a dispute.
 
 In the case of `reverse` swaps`; In the happy case, the client (us) will ALWAYS be required to build and spend from the script to claim on-chain funds.
-We would be the `receiver`, and the solution we have to create for the reverse swap is the `preimage` of a hash `and a `signature from our key.
+We would be the `receiver`, and the solution we have to create for the reverse swap is the `preimage` of a hash `and a `
+signature from our key.
 
-For the most part, normal swaps only require interaction with the `boltz.exchange` API, making it quite straightforward. In case of a dispute, we need to claim back funds from the on-chain script we funded, for which, we will need to build the script and spend it (refund tx).
+For the most part, normal swaps only require interaction with the `boltz.exchange` API, making it quite straightforward.
+In case of a dispute, we need to claim back funds from the on-chain script we funded, for which, we will need to build
+the script and spend it (refund tx).
 
-For the sake of unifying the implementation challenge, we will look at the standard procedure when doing a `reverse swap` happy case.
+For the sake of unifying the implementation challenge, we will look at the standard procedure when doing a
+`reverse swap` happy case.
 
 - [x] Create a `keypair.{seckey,pubkey}`
 - [x] Create a random secret (preimage)
 - [x] Create `hash`=sha256(preimage)
 - [x] Share `keypair.pubkey` and `hash` with `boltz.exchange`
-- [x] Boltz will use use this to create the script on their end and send it back to us as a `redeem_script` along with an LN `invoice` for us to pay and an onchain `address` that they will fund for us to claim
+- [x] Boltz will use use this to create the script on their end and send it back to us as a `redeem_script` along with
+  an LN `invoice` for us to pay and an onchain `address` that they will fund for us to claim
 - [x] Boltz will also return their `pubkey` and the `timeout` used
-- [x] verify the response from Boltz and the preimage used in the invoice (boltz cannot claim the invoice until the preimage is known)
+- [x] verify the response from Boltz and the preimage used in the invoice (boltz cannot claim the invoice until the
+  preimage is known)
 - [x] build the script on our end using: `our_pubkey, hash, boltz_pubkey and timeout`
 - [x] generate the address from the script and check for a match against the `address` provided by boltz
 - [x] ensure our script matches the `redeemScript` provided by boltz
@@ -94,33 +104,58 @@ The procedure for liquid is the same as Bitcoin, with the addition of blinding l
 - [bitcoin](https://docs.rs/bitcoin/0.30.0/bitcoin/index.html)
 - [elements](https://docs.rs/elements/0.22.0/elements/index.html)
 - [lightning-invoice](https://docs.rs/lightning-invoice/latest/lightning_invoice/)
-- [electrum-client](https://docs.rs/electrum-client/latest/electrum_client/)
+- Chain data access
+    - [electrum-client](https://docs.rs/electrum-client/latest/electrum_client/)
+    - [esplora](https://github.com/blockstream/esplora/blob/master/API.md)
 
 ## Resources
 
 - [teleport](https://github.com/utxo-teleport/teleport-transactions)
-A Proof of Concept on-chain utxo swap protocol.
+  A Proof of Concept on-chain utxo swap protocol.
 
 - [bitcoin-wallet](https://github.com/rust-bitcoin/rust-wallet)
-A simple rust bitcoin wallet
+  A simple rust bitcoin wallet
 
 - [rust-bitcoin-wallet](https://github.com/stevenroose/rust-bitcoin-wallet)
-Another old simple rust bitcoin wallet - only upto Psbt building
+  Another old simple rust bitcoin wallet - only upto Psbt building
 
 - [boltz](https://github.com/BoltzExchange/boltz-core/blob/master/lib/swap/Claim.ts)
-Boltz-core - solving the claim script
+  Boltz-core - solving the claim script
 
 - [tdryja-ct](https://www.youtube.com/watch?v=UySc4jxbqi4)
-Tadge Dryja's MIT Opencourseware presentation on Confidential Transactions
+  Tadge Dryja's MIT Opencourseware presentation on Confidential Transactions
 
 - [elements](https://github.com/ElementsProject/elements/blob/master/doc/elements-confidential-transactions.md)
-Docs from main elements repo on confidential transactions
+  Docs from main elements repo on confidential transactions
+
+## WASM
+
+This crate supports WASM.
+
+### Prerequisites
+
+#### Building WASM
+
+* Install [wasm-pack](https://rustwasm.github.io/docs/wasm-pack/): `cargo install wasm-pack`
+* (Mac Only) Install [llvm](https://llvm.org/): `brew install llvm`
+
+#### Testing WASM
+
+* Install the default testing browser [Firefox](https://www.mozilla.org/en-US/firefox/)
+* When testing on Safari:
+    * Enable safaridriver (might need sudo): `safaridriver --enable`
+* When testing on Chrome:
+    * Install chromedriver: `brew install chromedriver`
+
+    + (Mac Only) Allow use of chromeriver if the first run fails:
+      ` Settings > Privacy & Security > Allow use of chromedriver`
 
 ## test
 
-The best place to start diving into this repo is `tests` directory. This contains integration tests for bitcoin and liquid.
+The best place to start diving into this repo is `tests` directory. This contains integration tests for bitcoin and
+liquid.
 
-They contain the entire example of usage of the library. 
+They contain the entire example of usage of the library.
 
 Run all tests, except ignored tests
 
@@ -138,14 +173,15 @@ To run the complete reverse swap integration test:
 ```bash
 cargo test test_rsi -- --nocapture --include-ignored
 ```
-`test_rsi` is interactive. 
-It will block the terminal and prompt you to pay an ln invoice to proceed.
 
+`test_rsi` is interactive.
+It will block the terminal and prompt you to pay an ln invoice to proceed.
 
 ```bash
 cargo test test_normal_swap -- --nocapture --include-ignored
 
 ```
+
 `test_normal_swap` is ignored since it requires always using a new invoice or else it errors with 409
 
 So when manually testing, make sure you update the invoice variable.
@@ -163,6 +199,27 @@ export FUND=2100000
 lightning-cli --lightning-dir=/.lightning connect 029040945df331e634fba152ce6a21e3dfca87b68d275e078caeee4753f43e9acb 212.46.38.66:9736
 lightning-cli --lightning-dir=/.lightning fundchannel 029040945df331e634fba152ce6a21e3dfca87b68d275e078caeee4753f43e9acb $FUND
 ```
+
+### Testing WASM
+
+Firefox (default):
+
+```bash
+make wasm-test
+```
+
+Chrome:
+
+```bash
+make wasm-test-chrome
+```
+
+Safari:
+
+```bash
+make wasm-test-safari
+```
+
 ## Milestones
 
 - [x] NormalSwap  (BTC): Claim (Invoice paid)
@@ -180,18 +237,24 @@ This library makes the following assumptions:
 
 - Reverse swaps spend only 1 utxo
 
-In bitcoin, we use `listunspent` and take the first utxo only (array 0 index). The only case where something could go wrong here is if the script at any point has more than one utxo, which is unlikely. Boltz will always fund the script address with the entire amount.
+In bitcoin, we use `listunspent` and take the first utxo only (array 0 index). The only case where something could go
+wrong here is if the script at any point has more than one utxo, which is unlikely. Boltz will always fund the script
+address with the entire amount.
 
-When we fetch utxos now, we expect a single utxo funded with the exact amount of the swap. If the amount does not match or if there is more than one utxo, we do not claim the transaction.
+When we fetch utxos now, we expect a single utxo funded with the exact amount of the swap. If the amount does not match
+or if there is more than one utxo, we do not claim the transaction.
 
-An improvement on this is to make the utxos field in SwapTx use a Vec and make sweeps always use all available/spendable utxos. We should also ensure that the amount is equal to or more than the value of the swap and accordingly notify the user of the unexpected amount.
+An improvement on this is to make the utxos field in SwapTx use a Vec and make sweeps always use all available/spendable
+utxos. We should also ensure that the amount is equal to or more than the value of the swap and accordingly notify the
+user of the unexpected amount.
 
 - Bitcoin reverse swap sweep/drain is 1 output
 
 - Liquid reverse swap sweep/drain is 1 confidential output and 1 explicit fee output
 
 - Liquid reverse swap utxo is always confidential
-If boltz funds the swap script with Explicit values, the library will error. It currently only handles Confidential transactions.
+  If boltz funds the swap script with Explicit values, the library will error. It currently only handles Confidential
+  transactions.
 
 # Acknowledgment
 
@@ -200,5 +263,6 @@ This library is developed and maintained by Bull Bitcoin (www.bullbitcoin.com).
 Special thanks to:
 
 - [michael1011](https://github.com/michael1011) for guidance on implementation and swaps
-- [stratospher](https://github.com/stratospher) for contributions and pairing with us through understanding liquid confidential transactions
+- [stratospher](https://github.com/stratospher) for contributions and pairing with us through understanding liquid
+  confidential transactions
 - [RCasatta](https://github.com/RCasatta) for guidance on liquid