diff --git a/.github/workflows/ci-build.yml b/.github/workflows/ci-build.yml
index e233fcc1d..7514ae0c5 100644
--- a/.github/workflows/ci-build.yml
+++ b/.github/workflows/ci-build.yml
@@ -6,39 +6,47 @@ name: Build and Test
 on: [push]
 
 jobs:
-  build_and_test:
-    name: Build and Test
-    runs-on: ubuntu-latest
-
-    strategy:
-      matrix:
-        node-version: [11.x]
-
-    steps:
-    - name: Checkout repository
-      uses: actions/checkout@v2
-    
-    - name: Use Node.js ${{ matrix.node-version }}
-      uses: actions/setup-node@v1
-      with:
-        node-version: ${{ matrix.node-version }}
-    
-    - name: Cache node modules
-      uses: actions/cache@v1
-      env:
-        cache-name: cached-node-modules
-      with:
-        path: ~/work/0x-api/0x-api/node_modules
-        key: ${{ runner.os }}-build-${{ env.cache-name }}-${{ hashFiles('yarn.lock') }}
-    
-    - run: yarn install --frozen-lockfile
-    - run: yarn build
-    # Pull the docker images so that they don't need to be pulled in the tests.
-    - run: docker-compose pull
-    - run: yarn lint
-    - run: yarn test
-    - name: Save build artifacts
-      uses: actions/upload-artifact@v1
-      with:
-        name: lib
-        path: lib
+    build_and_test:
+        name: Build and Test
+        runs-on: ubuntu-latest
+
+        strategy:
+            matrix:
+                node-version: [11.x]
+
+        steps:
+            - name: Checkout repository
+              uses: actions/checkout@v2
+
+            - name: Use Node.js ${{ matrix.node-version }}
+              uses: actions/setup-node@v1
+              with:
+                  node-version: ${{ matrix.node-version }}
+
+            # Get the yarn cache directory and store it for cache hits
+            - name: Get yarn cache directory path
+              id: yarn-cache-dir-path
+              run: echo "::set-output name=dir::$(yarn cache dir)"
+
+            - name: Cache node modules
+              uses: actions/cache@v2
+              id: yarn-cache
+              env:
+                  cache-name: cached-node-modules
+              with:
+                  path: ${{ steps.yarn-cache-dir-path.outputs.dir }}
+                  key: ${{ runner.os }}-build-${{ hashFiles('yarn.lock') }}
+                  restore-keys: |
+                      ${{ runner.os }}-build-
+
+            - run: yarn install --frozen-lockfile
+            - run: yarn build
+            # Pull the docker images so that they don't need to be pulled in the tests.
+            - run: docker-compose pull
+            - run: yarn lint
+            - run: yarn test
+            - name: Save build artifacts
+              uses: actions/upload-artifact@v1
+              with:
+                  name: lib
+                  path: lib
diff --git a/src/services/swap_service.ts b/src/services/swap_service.ts
index 612db85b0..2c0821545 100644
--- a/src/services/swap_service.ts
+++ b/src/services/swap_service.ts
@@ -4,6 +4,7 @@ import {
     ProtocolFeeUtils,
     SwapQuote,
     SwapQuoteConsumer,
+    SwapQuoteGetOutputOpts,
     SwapQuoter,
     SwapQuoterOpts,
 } from '@0x/asset-swapper';
@@ -160,21 +161,19 @@ export class SwapService {
             attributedSwapQuote,
         );
 
-        // set the allowance target based on version. V0 is legacy param to support Nuo integrator
-        let allowanceTarget = NULL_ADDRESS;
-        if (isETHSell) {
-            switch (swapVersion) {
-                case SwapVersion.V0:
-                    allowanceTarget = this._contractAddresses.erc20Proxy;
-                    break;
-                case SwapVersion.V1:
-                    allowanceTarget = this._contractAddresses.exchangeProxyAllowanceTarget;
-                    break;
-                default:
-                    allowanceTarget = NULL_ADDRESS;
-                    break;
-            }
+        // set the allowance target based on version. V0 is legacy param to support transition to v1
+        let erc20AllowanceTarget = NULL_ADDRESS;
+        switch (swapVersion) {
+            case SwapVersion.V0:
+                erc20AllowanceTarget = this._contractAddresses.erc20Proxy;
+                break;
+            case SwapVersion.V1:
+                erc20AllowanceTarget = this._contractAddresses.exchangeProxyAllowanceTarget;
+                break;
+            default:
+                throw new Error(`Unsupported Swap version: ${swapVersion}`);
         }
+        const allowanceTarget = isETHSell ? NULL_ADDRESS : erc20AllowanceTarget;
 
         const apiSwapQuote: GetSwapQuoteResponse = {
             price,
@@ -390,8 +389,7 @@ export class SwapService {
                     takerAddress = await this._getExchangeProxyFlashWalletAsync();
                     break;
                 default:
-                    takerAddress = from || '';
-                    break;
+                    throw new Error(`Unsupported Swap version: ${swapVersion}`);
             }
             _rfqt = {
                 ...rfqt,
@@ -434,29 +432,28 @@ export class SwapService {
         affiliateAddress: string,
         swapVersion: SwapVersion,
     ): Promise<SwapQuoteResponsePartialTransaction> {
-        let extensionContractType;
+        let opts: Partial<SwapQuoteGetOutputOpts> = { useExtensionContract: ExtensionContractType.None };
         switch (swapVersion) {
             case SwapVersion.V0:
-                extensionContractType = isFromETH ? ExtensionContractType.Forwarder : ExtensionContractType.None;
+                if (isFromETH) {
+                    opts = { useExtensionContract: ExtensionContractType.Forwarder };
+                }
                 break;
             case SwapVersion.V1:
-                extensionContractType = ExtensionContractType.ExchangeProxy;
+                opts = {
+                    useExtensionContract: ExtensionContractType.ExchangeProxy,
+                    extensionContractOpts: { isFromETH, isToETH },
+                };
                 break;
             default:
-                break;
+                throw new Error(`Unsupported Swap version: ${swapVersion}`);
         }
 
-        const extensionContractOpts =
-            extensionContractType === ExtensionContractType.ExchangeProxy ? { isFromETH, isToETH } : undefined;
-
         const {
             calldataHexString: data,
             ethAmount: value,
             toAddress: to,
-        } = await this._swapQuoteConsumer.getCalldataOrThrowAsync(swapQuote, {
-            useExtensionContract: extensionContractType,
-            extensionContractOpts,
-        });
+        } = await this._swapQuoteConsumer.getCalldataOrThrowAsync(swapQuote, opts);
 
         const affiliatedData = serviceUtils.attributeCallData(data, affiliateAddress);
         return {