feat(autoswap): Reduce the number of awaits in init-autoswap.js (#119)

lib/ag-solo/init-autoswap.js

@@ -11,77 +11,128 @@ export default async ({ home, bundle }) => {
 
   console.log('*** AUTOSWAP');
 
+  // *********************
   // AUTOSWAP INSTALL
+  // *********************
 
   // 1. Load & install the autoswap contract.
+
   await upload(home, bundle, [ CONTRACT_NAME ]);
 
-  // 2. Get the autoswap contract installation.
-  const installationHandle = await home~.uploads~.get(CONTRACT_NAME);
+  // =====================
+  // === AWAITING TURN ===
+  // =====================
 
+  // 2. Get the autoswap contract installation.
   // 3. Store the contract installation in the registry.
-  const installationId = await home~.registrar~.register(CONTRACT_NAME, installationHandle);
+
+  const installationHandleP = home~.uploads~.get(CONTRACT_NAME);
+  const installationIdP = home~.registrar~.register(CONTRACT_NAME, installationHandleP);
+
+  const [installationHandle, installationId] 
+    = await Promise.all([installationHandleP, installationIdP]);
+
+  // =====================
+  // === AWAITING TURN ===
+  // =====================
 
   console.log('- Autoswap intallation', CONTRACT_NAME, '=>',  installationId);
 
+  // *********************
   // AUTOSWAP INSTANCE
-
-  // 1. Wallet has (at least 2?) purses. Get their assays
-  const purses = await Promise.all([
-    home~.wallet~.getPurse('Moola purse'),
-    home~.wallet~.getPurse('Simolean purse'),
+  // *********************
+
+  // 1. Purses, assays, payments.
+  const purse0P = home~.wallet~.getPurse('Moola purse');
+  const purse1P = home~.wallet~.getPurse('Simolean purse');
+  const assay0P = purse0P~.getAssay();
+  const assay1P = purse1P~.getAssay();
+  const payment0P = purse0P~.withdraw(INITIAL_LIQUIDITY);
+  const payment1P = purse1P~.withdraw(INITIAL_LIQUIDITY);
+
+  const [
+    purse0,
+    purse1,
+    assay0,
+    assay1,
+    payment0,
+    payment1
+  ] = await Promise.all([
+    purse0P,
+    purse1P,
+    assay0P,
+    assay1P,
+    payment0P,
+    payment1P
   ]);
-  const assays = await Promise.all(
-      purses.map(purse => purse~.getAssay()),
-  )
-
-  // 2. Contract instance.
-  try {
-    await home~.zoe~.makeInstance(installationHandle, { assays });
-  } catch(e) {}
-  const { instance, instanceHandle, terms } = await home~.zoe~.makeInstance(installationHandle, { assays });
-
-  // 3. Offer rules
-  const units = await Promise.all([
-    terms~.assays~.[0]~.makeUnits(INITIAL_LIQUIDITY),
-    terms~.assays~.[1]~.makeUnits(INITIAL_LIQUIDITY),
-    terms~.assays~.[2]~.makeUnits(0),
+
+  // =====================
+  // === AWAITING TURN ===
+  // =====================
+
+  // 2. Contract instance, contract assays.
+  const { instance, instanceHandle, terms: { assays } } = 
+    await home~.zoe~.makeInstance(installationHandle, { assays: [assay0, assay1] });
+
+  // =====================
+  // === AWAITING TURN ===
+  // =====================
+
+  // 3. Offer rules.
+  const unit0P = assays~.[0]~.makeUnits(INITIAL_LIQUIDITY);
+  const unit1P = assays~.[1]~.makeUnits(INITIAL_LIQUIDITY);
+  const unit2P = assays~.[2]~.makeUnits(0);
+
+  const [
+    unit0,
+    unit1, 
+    unit2,
+  ] = await Promise.all([
+    unit0P,
+    unit1P,
+    unit2P,
   ]);
 
+  // =====================
+  // === AWAITING TURN ===
+  // =====================
+
+  // 5. 
   const offerRules = harden({
     payoutRules: [
       {
         kind: 'offerExactly',
-        units: units[0],
+        units: unit0,
       },
       {
         kind: 'offerExactly',
-        units: units[1],
+        units: unit1,
       },
       {
         kind: 'wantAtLeast',
-        units: units[2],
+        units: unit2,
       },
     ],
     exitRule: {
       kind: 'onDemand',
     },
   });
 
-  // 4. Payments
-  const payments = await Promise.all([
-    purses[0]~.withdraw(INITIAL_LIQUIDITY),
-    purses[1]~.withdraw(INITIAL_LIQUIDITY),
-  ]);
+  const { escrowReceipt } = await home~.zoe~.escrow(offerRules, [payment0, payment1]);
 
-  // 5. Liquidities.
-  const { escrowReceipt } = await home~.zoe~.escrow(offerRules, payments);
-  const liquidityOk = await instance~.addLiquidity(escrowReceipt);
-  console.log(liquidityOk);
+  // =====================
+  // === AWAITING TURN ===
+  // =====================
+
+  const liquidityOkP = instance~.addLiquidity(escrowReceipt);
+  const instanceIdP = home~.registrar~.register(CONTRACT_NAME, instanceHandle);
 
-  if (liquidityOk) {
-    // Only store if the contract instance has liquidities.    
-    const instanceId = await home~.registrar~.register(CONTRACT_NAME, instanceHandle);
-    console.log('- Autoswap instance', CONTRACT_NAME, '=>', instanceId);
-  }
+  const [liquidityOk, instanceId] = await Promise.all([liquidityOkP, instanceIdP]); 
+
+  // =====================
+  // === AWAITING TURN ===
+  // =====================
+
+  console.log('- Autoswap instance', CONTRACT_NAME, '=>', instanceId);
+  console.log(liquidityOk);
 }