Initial GSN support (beta) (#1844)

* Add base Context contract

* Add GSNContext and tests

* Add RelayHub deployment to tests

* Add RelayProvider integration, complete GSNContext tests

* Switch dependency to openzeppelin-gsn-provider

* Add default txfee to provider

* Add basic signing recipient

* Sign more values

* Add comment clarifying RelayHub's msg.data

* Make context constructors internal

* Rename SigningRecipient to GSNRecipientSignedData

* Add ERC20Charge recipients

* Harcode RelayHub address into GSNContext

* Fix Solidity linter errors

* Run server from binary, use gsn-helpers to fund it

* Migrate to published @openzeppelin/gsn-helpers

* Silence false-positive compiler warning

* Use GSN helper assertions

* Rename meta-tx to gsn, take out of drafts

* Merge ERC20 charge recipients into a single one

* Rename GSNRecipients to Bouncers

* Add GSNBouncerUtils to decouple the bouncers from GSNRecipient

* Add _upgradeRelayHub

* Store RelayHub address using unstructored storage

* Add IRelayHub

* Add _withdrawDeposits to GSNRecipient

* Add relayHub version to recipient

* Make _acceptRelayedCall and _declineRelayedCall easier to use

* Rename GSNBouncerUtils to GSNBouncerBase, make it IRelayRecipient

* Improve GSNBouncerBase, make pre and post sender-protected and optional

* Fix GSNBouncerERC20Fee, add tests

* Add missing GSNBouncerSignature test

* Override transferFrom in __unstable__ERC20PrimaryAdmin

* Fix gsn dependencies in package.json

* Rhub address slot reduced by 1

* Rename relay hub changed event

* Use released gsn-provider

* Run relayer with short sleep of 1s instead of 100ms

* update package-lock.json

* clear circle cache

* use optimized gsn-provider

* update to latest @openzeppelin/gsn-provider

* replace with gsn dev provider

* remove relay server

* rename arguments in approveFunction

* fix GSNBouncerSignature test

* change gsn txfee

* initialize development provider only once

* update RelayHub interface

* adapt to new IRelayHub.withdraw

* update @openzeppelin/gsn-helpers

* update relayhub singleton address

* fix helper name

* set up gsn provider for coverage too

* lint

* Revert "set up gsn provider for coverage too"

This reverts commit 8a7b5be5f9.

* remove unused code

* add gsn provider to coverage

* move truffle contract options back out

* increase gas limit for coverage

* remove unreachable code

* add more gas for GSNContext test

* fix test suite name

* rename GSNBouncerBase internal API

* remove onlyRelayHub modifier

* add explicit inheritance

* remove redundant event

* update name of bouncers error codes enums

* add basic docs page for gsn contracts

* make gsn directory all caps

* add changelog entry

* lint

* enable test run to fail in coverage

scripts/test.sh

@@ -23,9 +23,13 @@ ganache_running() {
   nc -z localhost "$ganache_port"
 }
 
+relayer_running() {
+  nc -z localhost "$relayer_port"
+}
+
 start_ganache() {
-  # We define 10 accounts with balance 1M ether, needed for high-value tests.
   local accounts=(
+    # 10 accounts with balance 1M ether, needed for high-value tests.
     --account="0x2bdd21761a483f71054e14f5b827213567971c676928d9a1808cbfa4b7501200,1000000000000000000000000"
     --account="0x2bdd21761a483f71054e14f5b827213567971c676928d9a1808cbfa4b7501201,1000000000000000000000000"
     --account="0x2bdd21761a483f71054e14f5b827213567971c676928d9a1808cbfa4b7501202,1000000000000000000000000"
@@ -36,10 +40,14 @@ start_ganache() {
     --account="0x2bdd21761a483f71054e14f5b827213567971c676928d9a1808cbfa4b7501207,1000000000000000000000000"
     --account="0x2bdd21761a483f71054e14f5b827213567971c676928d9a1808cbfa4b7501208,1000000000000000000000000"
     --account="0x2bdd21761a483f71054e14f5b827213567971c676928d9a1808cbfa4b7501209,1000000000000000000000000"
+    # 3 accounts to be used for GSN matters.
+    --account="0x956b91cb2344d7863ea89e6945b753ca32f6d74bb97a59e59e04903ded14ad00,1000000000000000000000000"
+    --account="0x956b91cb2344d7863ea89e6945b753ca32f6d74bb97a59e59e04903ded14ad01,1000000000000000000000000"
+    --account="0x956b91cb2344d7863ea89e6945b753ca32f6d74bb97a59e59e04903ded14ad02,1000000000000000000000000"
   )
 
   if [ "$SOLIDITY_COVERAGE" = true ]; then
-    npx ganache-cli-coverage --emitFreeLogs true --allowUnlimitedContractSize true --gasLimit 0xfffffffffff --port "$ganache_port" "${accounts[@]}" > /dev/null &
+    npx ganache-cli-coverage --emitFreeLogs true --allowUnlimitedContractSize true --gasLimit 0xfffffffffffff --port "$ganache_port" "${accounts[@]}" > /dev/null &
   else
     npx ganache-cli --gasLimit 0xfffffffffff --port "$ganache_port" "${accounts[@]}" > /dev/null &
   fi
@@ -55,6 +63,12 @@ start_ganache() {
   echo "Ganache launched!"
 }
 
+setup_relayhub() {
+  npx oz-gsn deploy-relay-hub \
+    --ethereumNodeURL "http://localhost:$ganache_port" \
+    --from "0xbb49ad04422f9fa6a217f3ed82261b942f6981f7"
+}
+
 if ganache_running; then
   echo "Using existing ganache instance"
 else
@@ -64,6 +78,8 @@ fi
 
 npx truffle version
 
+setup_relayhub
+
 if [ "$SOLIDITY_COVERAGE" = true ]; then
   npx solidity-coverage
 else