make fractional base a constant

3 files changed, 16 insertions, 14 deletions

diff --git a/src/helpers.ts b/src/helpers.ts
index 2e7a701c3..d9b62aa22 100644
--- a/src/helpers.ts
+++ b/src/helpers.ts
@@ -23,7 +23,7 @@
 
 /// <reference path="../decl/urijs/URIjs.d.ts" />
 
-import {AmountJson} from "./types";
+import {AmountJson, Amounts} from "./types";
 import URI = uri.URI;
 
 export function substituteFulfillmentUrl(url: string, vars: any) {
@@ -34,7 +34,7 @@ export function substituteFulfillmentUrl(url: string, vars: any) {
 
 
 export function amountToPretty(amount: AmountJson): string {
-  let x = amount.value + amount.fraction / 1e6;
+  let x = amount.value + amount.fraction / Amounts.fractionalBase;
   return `${x} ${amount.currency}`;
 }
 
@@ -63,7 +63,7 @@ export function parsePrettyAmount(pretty: string): AmountJson|undefined {
   }
   return {
     value: parseInt(res[1], 10),
-    fraction: res[2] ? (parseFloat(`0.${res[2]}`) * 1e-6) : 0,
+    fraction: res[2] ? (parseFloat(`0.${res[2]}`) / Amounts.fractionalBase) : 0,
     currency: res[3]
   }
 }
diff --git a/src/renderHtml.tsx b/src/renderHtml.tsx
index 940d5c425..fe6646196 100644
--- a/src/renderHtml.tsx
+++ b/src/renderHtml.tsx
@@ -21,10 +21,10 @@
  */
 
 
-import {AmountJson, Contract} from "./types";
+import {AmountJson, Contract, Amounts} from "./types";
 
 export function prettyAmount(amount: AmountJson) {
-  let v = amount.value + amount.fraction / 1e6;
+  let v = amount.value + amount.fraction / Amounts.fractionalBase;
   return `${v.toFixed(2)} ${amount.currency}`;
 }
 
diff --git a/src/types.ts b/src/types.ts
index eb4a29788..b04453767 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -509,6 +509,8 @@ export type PayCoinInfo = Array<{ updatedCoin: CoinRecord, sig: CoinPaySig }>;
 
 
 export namespace Amounts {
+  export const fractionalBase = 1e8;
+
   export interface Result {
     amount: AmountJson;
     // Was there an over-/underflow?
@@ -533,18 +535,18 @@ export namespace Amounts {
 
   export function add(first: AmountJson, ...rest: AmountJson[]): Result {
     let currency = first.currency;
-    let value = first.value + Math.floor(first.fraction / 1e6);
+    let value = first.value + Math.floor(first.fraction / fractionalBase);
     if (value > Number.MAX_SAFE_INTEGER) {
       return { amount: getMaxAmount(currency), saturated: true };
     }
-    let fraction = first.fraction % 1e6;
+    let fraction = first.fraction % fractionalBase;
     for (let x of rest) {
       if (x.currency !== currency) {
         throw Error(`Mismatched currency: ${x.currency} and ${currency}`);
       }
 
-      value = value + x.value + Math.floor((fraction + x.fraction) / 1e6);
-      fraction = (fraction + x.fraction) % 1e6;
+      value = value + x.value + Math.floor((fraction + x.fraction) / fractionalBase);
+      fraction = (fraction + x.fraction) % fractionalBase;
       if (value > Number.MAX_SAFE_INTEGER) {
         return { amount: getMaxAmount(currency), saturated: true };
       }
@@ -567,7 +569,7 @@ export namespace Amounts {
           return { amount: { currency, value: 0, fraction: 0 }, saturated: true };
         }
         value--;
-        fraction += 1e6;
+        fraction += fractionalBase;
       }
       console.assert(fraction >= b.fraction);
       fraction -= b.fraction;
@@ -584,10 +586,10 @@ export namespace Amounts {
     if (a.currency !== b.currency) {
       throw Error(`Mismatched currency: ${a.currency} and ${b.currency}`);
     }
-    let av = a.value + Math.floor(a.fraction / 1e6);
-    let af = a.fraction % 1e6;
-    let bv = b.value + Math.floor(b.fraction / 1e6);
-    let bf = b.fraction % 1e6;
+    let av = a.value + Math.floor(a.fraction / fractionalBase);
+    let af = a.fraction % fractionalBase;
+    let bv = b.value + Math.floor(b.fraction / fractionalBase);
+    let bf = b.fraction % fractionalBase;
     switch (true) {
       case av < bv:
         return -1;