Extract healthcheck into its own class

This moves the whole checks if everything is running into its own class
and is no longer inside the different functions.
Makes the functions smaller and the healthcheck can be used from the
client only if wanted/needed.

lib/kredits.js

@@ -1,6 +1,8 @@
 const ethers = require('ethers');
 const RSVP = require('rsvp');
 
+const Healthcheck = require('./utils/healthcheck');
+
 const ABIS = {
   Contributors: require('./abis/Contributors.json'),
   Operator: require('./abis/Operator.json'),
@@ -49,15 +51,9 @@ class Kredits {
   static setup(provider, signer, ipfsConfig = null) {
     console.log('Kredits.setup() is deprecated use new Kredits().init() instead');
     let ipfs = new IPFS(ipfsConfig);
-
-    return ipfs._ipfsAPI.id().catch((error) => {
-      throw new Error(`IPFS node not available; config: ${JSON.stringify(ipfsConfig)} - ${error.message}`);
-    }).then(() => {
-
-      return new Kredits(provider, signer).init().then((kredits) => {
-        kredits.ipfs = ipfs;
-        return kredits;
-      });
+    return new Kredits(provider, signer).init().then((kredits) => {
+      kredits.ipfs = ipfs;
+      return kredits;
     });
   }
 
@@ -98,6 +94,10 @@ class Kredits {
 
     return this.contracts[name];
   }
+
+  healthcheck() {
+    return new Healthcheck(this).check();
+  }
 }
 
 module.exports = Kredits;

lib/utils/healthcheck.js

@@ -0,0 +1,28 @@
+class Healthcheck {
+  constructor(kredits) {
+    this.kredits = kredits;
+  }
+
+  check() {
+    return this.kredits.ipfs._ipfsAPI.id()
+      .catch((error) => {
+        throw new Error(`IPFS node not available; config: ${JSON.stringify(this.kredits.ipfs.config)} - ${error.message}`);
+      })
+      .then(() => {
+        let promises = Object.keys(this.kredits.contracts).map((name) => {
+          let contractWrapper = this.kredits.contracts[name];
+          return this.kredits.provider.getCode(contractWrapper.contract.address).then((code) => {
+            // not sure if we always get the same return value if the code is not available
+            // so checking if it is < 5 long
+            if (code === '0x00' || code.length < 5) {
+              throw new Error(`Contract for: ${name} not found at ${contractWrapper.contract.address} on network ${this.kredits.provider.chainId}`);
+            }
+            return true;
+          });
+        });
+        return Promise.all(promises);
+      });
+  }
+}
+
+module.exports = Healthcheck;