Merge pull request #376 from ethereum/document-rpc-test

Document RPC test

RPCTests/README.md

@@ -0,0 +1,70 @@
+See https://github.com/ethereum/cpp-ethereum/blob/7cc43bed7de890a496d7238092837c30c7e90729/scripts/runalltests.sh#L38 for how cpp-ethereum uses this.
+
+FAQ
+===
+
+Cannot find module
+------------------
+
+I get an error:
+```
+$ node main.js $workdir/cpp-ethereum/build/eth/eth
+module.js:471
+    throw err;
+    ^
+
+Error: Cannot find module '/home/yh/src/tests/RLPTests/main.js'
+    at Function.Module._resolveFilename (module.js:469:15)
+    at Function.Module._load (module.js:417:25)
+    at Module.runMain (module.js:604:10)
+    at run (bootstrap_node.js:393:7)
+    at startup (bootstrap_node.js:150:9)
+    at bootstrap_node.js:508:3
+```
+
+Answer: if your `main.js` is in your current directory, use `./main.js` instead of just `main.js`.
+
+
+Cannot find module web3
+-----------------------
+
+I get an error:
+```
+$ node ./main.js ~/src/cpp-ethereum/build/eth/eth
+(node:27647) UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 1): Error: Cannot find module 'web3'
+```
+
+Answer: `npm install web3`
+
+
+Some tests fail
+---------------
+
+```
+$ node ./main.js ~/src/cpp-ethereum/build/eth/eth
+TEST_newAccount OK
+TEST_addPeerOnNode2 OK
+TEST_getPeerCountOnNode1 OK
+TEST_mineBlockOnNode1 FAILED
+TEST_mineBlockOnNode1 FAILED
+TEST_getBlockHashOnNode2 OK
+TEST_mineBlockOnNode2 FAILED
+TEST_mineBlockOnNode2 FAILED
+TEST_getBlockHashOnNode1 OK
+(node:30406) UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 1): Error: Callback was already called.
+```
+
+Answer: everybody experiences these failures now. They are being tracked in [issue 377](https://github.com/ethereum/tests/issues/377).
+
+
+Do these failures indicate bugs in cpp-ethereum or in the test?
+---------------------------------------------------------------
+
+Different opinions exist
+* https://github.com/ethereum/tests/pull/376#issuecomment-349799774
+* https://github.com/ethereum/tests/pull/376#issuecomment-349933405
+
+Has any other clients been tested with this?
+--------------------------------------------
+
+No.