From e1f19a1832120a8f65d4deb74b122e295fa47f37 Mon Sep 17 00:00:00 2001
From: bumi <hello@michaelbumann.com>
Date: Sun, 15 Apr 2018 16:45:09 +0200
Subject: [PATCH 1/2] Fail smarter with better error handling

This should give more insights in case of an error during loading data
from Ethereum and IPFS.
---
 app/lib/kredits/kredits.js    | 45 +++++++++++++++++++++++++++--------
 app/lib/kredits/utils/ipfs.js |  1 -
 app/routes/application.js     |  2 ++
 3 files changed, 37 insertions(+), 11 deletions(-)

diff --git a/app/lib/kredits/kredits.js b/app/lib/kredits/kredits.js
index b087371..7001a9a 100644
--- a/app/lib/kredits/kredits.js
+++ b/app/lib/kredits/kredits.js
@@ -27,22 +27,44 @@ export default class Kredits {
     this.ipfsConfig = ipfsConfig;
     this.ipfs = new IPFS(ipfsConfig);
 
-    let registryContract = this.initRegistryContract(provider);
+    return this.ipfs._ipfsAPI.id().catch((error) => {
+      throw new Error(`IPFS node not available; config: ${JSON.stringify(ipfsConfig)} - ${error.message}`);
+    }).then(() => {
 
-    let addresses = Object.keys(contracts).reduce((mem, name) => {
-      let contractName = capitalize(name);
-      mem[contractName] = registryContract.functions.getProxyFor(contractName);
-      return mem;
-    }, {});
+      let registryContract = this.initRegistryContract(provider);
 
-    return RSVP.hash(addresses)
-      .then((addresses) => {
-        return new Kredits(provider, signer, addresses);
-      });
+      let addresses = Object.keys(contracts).reduce((mem, name) => {
+        let contractName = capitalize(name);
+        mem[contractName] = registryContract.functions.getProxyFor(contractName).catch((error) => {
+          throw new Error(`Failed to get address for ${contractName} from registry at ${registryContract.address}
+            - correct registry? does it have version entry? - ${error.message}`
+          );
+        });
+        return mem;
+      }, {});
+
+      return RSVP.hash(addresses)
+        .then((addresses) => {
+          return new Kredits(provider, signer, addresses);
+        });
+    });
   }
 
   static initRegistryContract(provider) {
     let address = addresses['Registry'][provider.chainId];
+    if (!address) {
+      throw new Error(`Registry address not found; invalid network?
+        requested network: ${provider.chainId}
+        supported networks: ${Object.keys(addresses['Registry'])}
+      `);
+    }
+    provider.getCode(address).then((code) => {
+      // not sure if we always get the same return value of the code is not available
+      // that's why checking if it is < 5 long
+      if (code === '0x00' || code.length < 5) {
+        throw new Error(`Registry not found at ${address} on network ${provider.chainId}`);
+      }
+    });
     let abi = abis['Registry'];
     console.log('Initialize registry contract:', address, abi, provider);
     return new ethers.Contract(address, abi, provider);
@@ -69,6 +91,9 @@ export default class Kredits {
 
     let contractName = capitalize(name);
     let address = this.addresses[contractName];
+    if (!address || !abis[contractName]) {
+      throw new Error('Address or ABI not found for ' + contractName);
+    }
     let contract = new ethers.Contract(address, abis[contractName], this.signer);
     this.contracts[name] = new contracts[contractName](contract);
 
diff --git a/app/lib/kredits/utils/ipfs.js b/app/lib/kredits/utils/ipfs.js
index 5a2a7e4..bc6ccda 100644
--- a/app/lib/kredits/utils/ipfs.js
+++ b/app/lib/kredits/utils/ipfs.js
@@ -51,5 +51,4 @@ export default class IPFS {
     return multihashes.encode(digest, hashData.hashFunction, hashData.hashSize);
   }
 
-
 }
diff --git a/app/routes/application.js b/app/routes/application.js
index 9371c64..602cdbd 100644
--- a/app/routes/application.js
+++ b/app/routes/application.js
@@ -13,6 +13,8 @@ export default Route.extend({
           transition.retry();
         }
       }
+    }).catch((error) => {
+      console.log('Error initializing Kredits', error);
     });
   },
 });

From 7e6c6a037d3e0ce73034cc56ee1c8e5d735ee6f5 Mon Sep 17 00:00:00 2001
From: bumi <hello@michaelbumann.com>
Date: Sun, 15 Apr 2018 18:02:52 +0200
Subject: [PATCH 2/2] code style. use interpolation syntax

---
 app/lib/kredits/kredits.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/app/lib/kredits/kredits.js b/app/lib/kredits/kredits.js
index 7001a9a..46a893f 100644
--- a/app/lib/kredits/kredits.js
+++ b/app/lib/kredits/kredits.js
@@ -92,7 +92,7 @@ export default class Kredits {
     let contractName = capitalize(name);
     let address = this.addresses[contractName];
     if (!address || !abis[contractName]) {
-      throw new Error('Address or ABI not found for ' + contractName);
+      throw new Error(`Address or ABI not found for ${contractName}`);
     }
     let contract = new ethers.Contract(address, abis[contractName], this.signer);
     this.contracts[name] = new contracts[contractName](contract);