Improve all the comments for the subproviders public methods

9 files changed, 199 insertions, 115 deletions

diff --git a/packages/subproviders/src/index.ts b/packages/subproviders/src/index.ts
index 0dc053286..d88792fd0 100644
--- a/packages/subproviders/src/index.ts
+++ b/packages/subproviders/src/index.ts
@@ -24,7 +24,7 @@ export {
 
 /**
  * A factory method for creating a LedgerEthereumClient usable in a browser context.
- * @return LedgerEthereumClient A browser client
+ * @return LedgerEthereumClient A browser client for the LedgerSubprovider
  */
 export async function ledgerEthereumBrowserClientFactoryAsync(): Promise<LedgerEthereumClient> {
     const ledgerConnection = await TransportU2F.create();
diff --git a/packages/subproviders/src/subproviders/empty_wallet_subprovider.ts b/packages/subproviders/src/subproviders/empty_wallet_subprovider.ts
index d5d03a4ac..38972b6cf 100644
--- a/packages/subproviders/src/subproviders/empty_wallet_subprovider.ts
+++ b/packages/subproviders/src/subproviders/empty_wallet_subprovider.ts
@@ -4,15 +4,14 @@ import { Callback, ErrorCallback } from '../types';
 
 import { Subprovider } from './subprovider';
 
-/*
- * This class implements the web3-provider-engine subprovider interface and returns
- * that the provider has no addresses when queried.
- * Source: https://github.com/MetaMask/provider-engine/blob/master/subproviders/subprovider.js
+/**
+ * This class implements the [web3-provider-engine](https://github.com/MetaMask/provider-engine) subprovider interface.
+ * It intercepts the `eth_accounts` JSON RPC requests and never returns any addresses when queried.
  */
 export class EmptyWalletSubprovider extends Subprovider {
     // This method needs to be here to satisfy the interface but linter wants it to be static.
-    // tslint:disable-next-line:prefer-function-over-method
-    public handleRequest(payload: Web3.JSONRPCRequestPayload, next: Callback, end: ErrorCallback) {
+    // tslint:disable-next-line:prefer-function-over-method underscore-private-and-protected
+    private handleRequest(payload: Web3.JSONRPCRequestPayload, next: Callback, end: ErrorCallback) {
         switch (payload.method) {
             case 'eth_accounts':
                 end(null, []);
diff --git a/packages/subproviders/src/subproviders/fake_gas_estimate_subprovider.ts b/packages/subproviders/src/subproviders/fake_gas_estimate_subprovider.ts
index faec2d9e5..8241e58f2 100644
--- a/packages/subproviders/src/subproviders/fake_gas_estimate_subprovider.ts
+++ b/packages/subproviders/src/subproviders/fake_gas_estimate_subprovider.ts
@@ -4,23 +4,28 @@ import { Callback, ErrorCallback } from '../types';
 
 import { Subprovider } from './subprovider';
 
-/*
- * This class implements the web3-provider-engine subprovider interface and returns
- * the constant gas estimate when queried.
- * HACK: We need this so that our tests don't use testrpc gas estimation which sometimes kills the node.
- * Source: https://github.com/trufflesuite/ganache-cli/issues/417
- * Source: https://github.com/trufflesuite/ganache-cli/issues/437
- * Source: https://github.com/MetaMask/provider-engine/blob/master/subproviders/subprovider.js
+// HACK: We need this so that our tests don't use testrpc gas estimation which sometimes kills the node.
+// Source: https://github.com/trufflesuite/ganache-cli/issues/417
+// Source: https://github.com/trufflesuite/ganache-cli/issues/437
+// Source: https://github.com/MetaMask/provider-engine/blob/master/subproviders/subprovider.js
+
+/**
+ * This class implements the [web3-provider-engine](https://github.com/MetaMask/provider-engine) subprovider interface.
+ * It intercepts the `eth_estimateGas` JSON RPC call and always returns a constant gas amount when queried.
  */
 export class FakeGasEstimateSubprovider extends Subprovider {
     private _constantGasAmount: number;
+    /**
+     * Instantiates an instance of the FakeGasEstimateSubprovider
+     * @param constantGasAmount The constant gas amount you want returned
+     */
     constructor(constantGasAmount: number) {
         super();
         this._constantGasAmount = constantGasAmount;
     }
     // This method needs to be here to satisfy the interface but linter wants it to be static.
-    // tslint:disable-next-line:prefer-function-over-method
-    public handleRequest(payload: Web3.JSONRPCRequestPayload, next: Callback, end: ErrorCallback) {
+    // tslint:disable-next-line:prefer-function-over-method underscore-private-and-protected
+    private handleRequest(payload: Web3.JSONRPCRequestPayload, next: Callback, end: ErrorCallback) {
         switch (payload.method) {
             case 'eth_estimateGas':
                 end(null, this._constantGasAmount);
diff --git a/packages/subproviders/src/subproviders/ganache.ts b/packages/subproviders/src/subproviders/ganache.ts
index 6ff939674..22ac5e1e2 100644
--- a/packages/subproviders/src/subproviders/ganache.ts
+++ b/packages/subproviders/src/subproviders/ganache.ts
@@ -5,20 +5,23 @@ import { Callback, ErrorCallback } from '../types';
 
 import { Subprovider } from './subprovider';
 
-/*
- * This class implements the web3-provider-engine subprovider interface and returns
- * the provider connected to a in-process ganache.
- * Source: https://github.com/MetaMask/provider-engine/blob/master/subproviders/subprovider.js
+/**
+ * This class implements the [web3-provider-engine](https://github.com/MetaMask/provider-engine) subprovider interface.
+ * It intercepts all JSON RPC requests and relays them to an in-process ganache instance.
  */
 export class GanacheSubprovider extends Subprovider {
     private _ganacheProvider: Web3.Provider;
+    /**
+     * Instantiates a GanacheSubprovider
+     * @param opts The desired opts with which to instantiate the Ganache provider
+     */
     constructor(opts: any) {
         super();
         this._ganacheProvider = Ganache.provider(opts);
     }
     // This method needs to be here to satisfy the interface but linter wants it to be static.
-    // tslint:disable-next-line:prefer-function-over-method
-    public handleRequest(payload: Web3.JSONRPCRequestPayload, next: Callback, end: ErrorCallback) {
+    // tslint:disable-next-line:prefer-function-over-method underscore-private-and-protected
+    private handleRequest(payload: Web3.JSONRPCRequestPayload, next: Callback, end: ErrorCallback) {
         this._ganacheProvider.sendAsync(payload, (err: Error | null, result: any) => {
             end(err, result && result.result);
         });
diff --git a/packages/subproviders/src/subproviders/injected_web3.ts b/packages/subproviders/src/subproviders/injected_web3.ts
index ec7304cb7..3e3744d5c 100644
--- a/packages/subproviders/src/subproviders/injected_web3.ts
+++ b/packages/subproviders/src/subproviders/injected_web3.ts
@@ -5,19 +5,25 @@ import { Callback, ErrorCallback } from '../types';
 
 import { Subprovider } from './subprovider';
 
-/*
- * This class implements the web3-provider-engine subprovider interface and forwards
- * requests involving user accounts (getAccounts, sendTransaction, etc...) to the injected
- * provider instance in their browser.
- * Source: https://github.com/MetaMask/provider-engine/blob/master/subproviders/subprovider.js
+/**
+ * This class implements the [web3-provider-engine](https://github.com/MetaMask/provider-engine)
+ * subprovider interface. It forwards JSON RPC requests involving user accounts (getAccounts,
+ * sendTransaction, etc...) to the provider instance supplied at instantiation. All other requests
+ * are passed onwards for subsequent subproviders to handle.
  */
 export class InjectedWeb3Subprovider extends Subprovider {
     private _injectedWeb3: Web3;
-    constructor(subprovider: Web3.Provider) {
+    /**
+     * Instantiates a new InjectedWeb3Subprovider
+     * @param provider Web3 provider that should handle  all user account related requests
+     */
+    constructor(provider: Web3.Provider) {
         super();
-        this._injectedWeb3 = new Web3(subprovider);
+        this._injectedWeb3 = new Web3(provider);
     }
-    public handleRequest(payload: Web3.JSONRPCRequestPayload, next: Callback, end: ErrorCallback) {
+    // This method needs to be here to satisfy the interface but linter wants it to be static.
+    // tslint:disable-next-line:prefer-function-over-method underscore-private-and-protected
+    private handleRequest(payload: Web3.JSONRPCRequestPayload, next: Callback, end: ErrorCallback) {
         switch (payload.method) {
             case 'web3_clientVersion':
                 this._injectedWeb3.version.getNode(end);
diff --git a/packages/subproviders/src/subproviders/ledger.ts b/packages/subproviders/src/subproviders/ledger.ts
index 95217c84d..75c73c4de 100644
--- a/packages/subproviders/src/subproviders/ledger.ts
+++ b/packages/subproviders/src/subproviders/ledger.ts
@@ -24,6 +24,11 @@ const DEFAULT_NUM_ADDRESSES_TO_FETCH = 10;
 const ASK_FOR_ON_DEVICE_CONFIRMATION = false;
 const SHOULD_GET_CHAIN_CODE = true;
 
+/**
+ * Subprovider for interfacing with a user's [Ledger Nano S](https://www.ledgerwallet.com/products/ledger-nano-s).
+ * This subprovider intercepts all account related RPC requests (e.g message/transaction signing, etc...) and
+ * re-routes them to a Ledger device plugged into the users computer.
+ */
 export class LedgerSubprovider extends Subprovider {
     private _nonceLock = new Lock();
     private _connectionLock = new Lock();
@@ -38,6 +43,11 @@ export class LedgerSubprovider extends Subprovider {
             throw new Error(LedgerSubproviderErrors.SenderInvalidOrNotSupplied);
         }
     }
+    /**
+     * Instantiates a LedgerSubprovider
+     * @param config Several available configurations
+     * @return LedgerSubprovider instance
+     */
     constructor(config: LedgerSubproviderConfigs) {
         super();
         this._networkId = config.networkId;
@@ -50,84 +60,38 @@ export class LedgerSubprovider extends Subprovider {
                 : ASK_FOR_ON_DEVICE_CONFIRMATION;
         this._derivationPathIndex = 0;
     }
+    /**
+     * Retrieve the set derivation path
+     * @returns derivation path
+     */
     public getPath(): string {
         return this._derivationPath;
     }
+    /**
+     * Set a desired derivation path when computing the available user addresses
+     * @param derivationPath The desired derivation path (e.g `44'/60'/0'`)
+     */
     public setPath(derivationPath: string) {
         this._derivationPath = derivationPath;
     }
+    /**
+     * Set the final derivation path index. If a user wishes to sign a message with the
+     * 6th address in a derivation path, before calling `signPersonalMessageAsync`, you must
+     * call this method with pathIndex `6`.
+     * @param pathIndex Desired derivation path index
+     */
     public setPathIndex(pathIndex: number) {
         this._derivationPathIndex = pathIndex;
     }
-    // Required to implement this public interface which doesn't conform to our linting rule.
-    // tslint:disable-next-line:async-suffix
-    public async handleRequest(
-        payload: Web3.JSONRPCRequestPayload,
-        next: Callback,
-        end: (err: Error | null, result?: any) => void,
-    ) {
-        let accounts;
-        let txParams;
-        switch (payload.method) {
-            case 'eth_coinbase':
-                try {
-                    accounts = await this.getAccountsAsync();
-                    end(null, accounts[0]);
-                } catch (err) {
-                    end(err);
-                }
-                return;
-
-            case 'eth_accounts':
-                try {
-                    accounts = await this.getAccountsAsync();
-                    end(null, accounts);
-                } catch (err) {
-                    end(err);
-                }
-                return;
-
-            case 'eth_sendTransaction':
-                txParams = payload.params[0];
-                try {
-                    LedgerSubprovider._validateSender(txParams.from);
-                    const result = await this._sendTransactionAsync(txParams);
-                    end(null, result);
-                } catch (err) {
-                    end(err);
-                }
-                return;
-
-            case 'eth_signTransaction':
-                txParams = payload.params[0];
-                try {
-                    const result = await this._signTransactionWithoutSendingAsync(txParams);
-                    end(null, result);
-                } catch (err) {
-                    end(err);
-                }
-                return;
-
-            case 'eth_sign':
-            case 'personal_sign':
-                const data = payload.method === 'eth_sign' ? payload.params[1] : payload.params[0];
-                try {
-                    if (_.isUndefined(data)) {
-                        throw new Error(LedgerSubproviderErrors.DataMissingForSignPersonalMessage);
-                    }
-                    assert.isHexString('data', data);
-                    const ecSignatureHex = await this.signPersonalMessageAsync(data);
-                    end(null, ecSignatureHex);
-                } catch (err) {
-                    end(err);
-                }
-                return;
-
-            default:
-                next();
-                return;
-        }
-    }
+    /**
+     * Retrieve a users Ledger accounts. The accounts are derived from the derivationPath,
+     * master public key and chainCode. Because of this, you can request as many accounts
+     * as you wish and it only requires a single request to the Ledger device. This method
+     * is automatically called when issuing a `eth_accounts` JSON RPC request via your providerEngine
+     * instance.
+     * @param numberOfAccounts Number of accounts to retrieve (default: 10)
+     * @return An array of accounts
+     */
     public async getAccountsAsync(numberOfAccounts: number = DEFAULT_NUM_ADDRESSES_TO_FETCH): Promise<string[]> {
         this._ledgerClientIfExists = await this._createLedgerClientAsync();
 
@@ -159,6 +123,14 @@ export class LedgerSubprovider extends Subprovider {
         }
         return accounts;
     }
+    /**
+     * Sign a transaction with the Ledger. If you've added the LedgerSubprovider to your
+     * app's provider, you can simply send an `eth_sendTransaction` JSON RPC request, and
+     * this method will be called auto-magically. If you are not using this via a ProviderEngine
+     * instance, you can call it directly.
+     * @param txParams Parameters of the transaction to sign
+     * @return Signed transaction hex string
+     */
     public async signTransactionAsync(txParams: PartialTxParams): Promise<string> {
         this._ledgerClientIfExists = await this._createLedgerClientAsync();
 
@@ -194,6 +166,16 @@ export class LedgerSubprovider extends Subprovider {
             throw err;
         }
     }
+    /**
+     * Sign a personal Ethereum signed message. The signing address will be to one
+     * retrieved given a derivationPath and pathIndex set on the subprovider.
+     * The Ledger adds the Ethereum signed message prefix on-device.  If you've added
+     * the LedgerSubprovider to your app's provider, you can simply send an `eth_sign`
+     * or `personal_sign` JSON RPC request, and this method will be called auto-magically.
+     * If you are not using this via a ProviderEngine instance, you can call it directly.
+     * @param data Message to sign
+     * @return Signature hex string (order: rsv)
+     */
     public async signPersonalMessageAsync(data: string): Promise<string> {
         this._ledgerClientIfExists = await this._createLedgerClientAsync();
         try {
@@ -215,6 +197,75 @@ export class LedgerSubprovider extends Subprovider {
             throw err;
         }
     }
+    // Required to implement this public interface which doesn't conform to our linting rule.
+    // tslint:disable-next-line:async-suffix underscore-private-and-protected
+    private async handleRequest(
+        payload: Web3.JSONRPCRequestPayload,
+        next: Callback,
+        end: (err: Error | null, result?: any) => void,
+    ) {
+        let accounts;
+        let txParams;
+        switch (payload.method) {
+            case 'eth_coinbase':
+                try {
+                    accounts = await this.getAccountsAsync();
+                    end(null, accounts[0]);
+                } catch (err) {
+                    end(err);
+                }
+                return;
+
+            case 'eth_accounts':
+                try {
+                    accounts = await this.getAccountsAsync();
+                    end(null, accounts);
+                } catch (err) {
+                    end(err);
+                }
+                return;
+
+            case 'eth_sendTransaction':
+                txParams = payload.params[0];
+                try {
+                    LedgerSubprovider._validateSender(txParams.from);
+                    const result = await this._sendTransactionAsync(txParams);
+                    end(null, result);
+                } catch (err) {
+                    end(err);
+                }
+                return;
+
+            case 'eth_signTransaction':
+                txParams = payload.params[0];
+                try {
+                    const result = await this._signTransactionWithoutSendingAsync(txParams);
+                    end(null, result);
+                } catch (err) {
+                    end(err);
+                }
+                return;
+
+            case 'eth_sign':
+            case 'personal_sign':
+                const data = payload.method === 'eth_sign' ? payload.params[1] : payload.params[0];
+                try {
+                    if (_.isUndefined(data)) {
+                        throw new Error(LedgerSubproviderErrors.DataMissingForSignPersonalMessage);
+                    }
+                    assert.isHexString('data', data);
+                    const ecSignatureHex = await this.signPersonalMessageAsync(data);
+                    end(null, ecSignatureHex);
+                } catch (err) {
+                    end(err);
+                }
+                return;
+
+            default:
+                next();
+                return;
+        }
+    }
     private _getDerivationPath() {
         const derivationPath = `${this.getPath()}/${this._derivationPathIndex}`;
         return derivationPath;
diff --git a/packages/subproviders/src/subproviders/nonce_tracker.ts b/packages/subproviders/src/subproviders/nonce_tracker.ts
index 82eab4a9a..b51ba4ac8 100644
--- a/packages/subproviders/src/subproviders/nonce_tracker.ts
+++ b/packages/subproviders/src/subproviders/nonce_tracker.ts
@@ -10,13 +10,13 @@ import { Callback, ErrorCallback, NextCallback, NonceSubproviderErrors } from '.
 
 import { Subprovider } from './subprovider';
 
-// We do not export this since this is not our error, and we do not throw this error
 const NONCE_TOO_LOW_ERROR_MESSAGE = 'Transaction nonce is too low';
-/*
-    This class is heavily inspiried by the Web3ProviderEngine NonceSubprovider
-    We have added the additional feature of clearing any nonce balues when an error message
-    describes a nonce value being too low.
-*/
+
+/**
+ * This class implements the [web3-provider-engine](https://github.com/MetaMask/provider-engine) subprovider interface.
+ * It is heavily inspired by the [NonceSubprovider](https://github.com/MetaMask/provider-engine/blob/master/subproviders/nonce-tracker.js).
+ * We added the additional feature of clearing the cached nonce value when a `nonce value too low` error occurs.
+ */
 export class NonceTrackerSubprovider extends Subprovider {
     private _nonceCache: { [address: string]: string } = {};
     private static _reconstructTransaction(payload: Web3.JSONRPCRequestPayload): EthereumTx {
@@ -47,8 +47,8 @@ export class NonceTrackerSubprovider extends Subprovider {
         }
     }
     // Required to implement this public interface which doesn't conform to our linting rule.
-    // tslint:disable-next-line:async-suffix
-    public async handleRequest(
+    // tslint:disable-next-line:prefer-function-over-method underscore-private-and-protected
+    private async handleRequest(
         payload: Web3.JSONRPCRequestPayload,
         next: NextCallback,
         end: ErrorCallback,
diff --git a/packages/subproviders/src/subproviders/redundant_rpc.ts b/packages/subproviders/src/subproviders/redundant_rpc.ts
index dacd1c2c5..2b84d223b 100644
--- a/packages/subproviders/src/subproviders/redundant_rpc.ts
+++ b/packages/subproviders/src/subproviders/redundant_rpc.ts
@@ -7,6 +7,11 @@ import { Callback } from '../types';
 
 import { Subprovider } from './subprovider';
 
+/**
+ * This class implements the [web3-provider-engine](https://github.com/MetaMask/provider-engine) subprovider interface.
+ * It attempts to handle each JSON RPC request by sequentially attempting to receive a valid response from one of a
+ * set of JSON RPC endpoints.
+ */
 export class RedundantRPCSubprovider extends Subprovider {
     private _rpcs: RpcSubprovider[];
     private static async _firstSuccessAsync(
@@ -28,6 +33,10 @@ export class RedundantRPCSubprovider extends Subprovider {
             throw lastErr;
         }
     }
+    /**
+     * Instantiates a new RedundantRPCSubprovider
+     * @param endpoints JSON RPC endpoints to attempt. Attempts are made in the order of the endpoints.
+     */
     constructor(endpoints: string[]) {
         super();
         this._rpcs = _.map(endpoints, endpoint => {
@@ -37,8 +46,8 @@ export class RedundantRPCSubprovider extends Subprovider {
         });
     }
     // Required to implement this public interface which doesn't conform to our linting rule.
-    // tslint:disable-next-line:async-suffix
-    public async handleRequest(
+    // tslint:disable-next-line:prefer-function-over-method underscore-private-and-protected
+    private async handleRequest(
         payload: Web3.JSONRPCRequestPayload,
         next: Callback,
         end: (err: Error | null, data?: any) => void,
diff --git a/packages/subproviders/src/subproviders/subprovider.ts b/packages/subproviders/src/subproviders/subprovider.ts
index 4a224fc4e..0b30c6397 100644
--- a/packages/subproviders/src/subproviders/subprovider.ts
+++ b/packages/subproviders/src/subproviders/subprovider.ts
@@ -2,10 +2,9 @@ import promisify = require('es6-promisify');
 import * as Web3 from 'web3';
 
 import { JSONRPCRequestPayloadWithMethod } from '../types';
-/*
- * A version of the base class Subprovider found in providerEngine
+/**
+ * A altered version of the base class Subprovider found in [web3-provider-engine](https://github.com/MetaMask/provider-engine).
  * This one has an async/await `emitPayloadAsync` and also defined types.
- * Altered version of: https://github.com/MetaMask/provider-engine/blob/master/subproviders/subprovider.js
  */
 export class Subprovider {
     private _engine: any;
@@ -31,9 +30,13 @@ export class Subprovider {
         };
         return finalPayload;
     }
-    public setEngine(engine: any): void {
-        this._engine = engine;
-    }
+    /**
+     * Emits a JSON RPC payload that will then be handled by the ProviderEngine instance
+     * this subprovider is a part of. The payload will cascade down the subprovider middleware
+     * stack until finding the responsible entity for handling the request.
+     * @param payload JSON RPC payload
+     * @returns JSON RPC response payload
+     */
     public async emitPayloadAsync(
         payload: Partial<JSONRPCRequestPayloadWithMethod>,
     ): Promise<Web3.JSONRPCResponsePayload> {
@@ -41,4 +44,12 @@ export class Subprovider {
         const response = await promisify(this._engine.sendAsync, this._engine)(finalPayload);
         return response;
     }
+    /**
+     * Set's the subprovider's engine to the ProviderEngine it is added to.
+     * This is only called within the ProviderEngine source code
+     */
+    // tslint:disable-next-line:underscore-private-and-protected
+    private setEngine(engine: any): void {
+        this._engine = engine;
+    }
 }