CORPORATION: Remove non-empty-string condition in sell modals

src/Corporation/Actions.ts

@@ -208,6 +208,14 @@ export function acceptInvestmentOffer(corporation: Corporation): void {
 }
 
 export function convertPriceString(price: string): string {
+  /**
+   * This is a common error. We should check it to get a "user-friendly" error message. If we pass an empty string to
+   * eval(), it will return undefined, and the "is-it-a-valid-number" following check will throw an unhelpful error
+   * message.
+   */
+  if (price === "") {
+    throw new Error("Price cannot be an empty string.");
+  }
   /**
    * Replace invalid characters. Only accepts:
    * - Digit characters
@@ -239,6 +247,14 @@ export function convertPriceString(price: string): string {
 }
 
 export function convertAmountString(amount: string): string {
+  /**
+   * This is a common error. We should check it to get a "user-friendly" error message. If we pass an empty string to
+   * eval(), it will return undefined, and the "is-it-a-valid-number" following check will throw an unhelpful error
+   * message.
+   */
+  if (amount === "") {
+    throw new Error("Amount cannot be an empty string.");
+  }
   /**
    * Replace invalid characters. Only accepts:
    * - Digit characters

src/Corporation/ui/modals/SellMaterialModal.tsx

@@ -31,16 +31,10 @@ export function SellMaterialModal(props: IProps): React.ReactElement {
   }
 
   function onAmtChange(event: React.ChangeEvent<HTMLInputElement>): void {
-    if (event.target.value === "") {
-      return;
-    }
     setAmt(event.target.value);
   }
 
   function onPriceChange(event: React.ChangeEvent<HTMLInputElement>): void {
-    if (event.target.value === "") {
-      return;
-    }
     setPrice(event.target.value);
   }
 

src/Corporation/ui/modals/SellProductModal.tsx

@@ -39,16 +39,10 @@ export function SellProductModal(props: IProps): React.ReactElement {
   }
 
   function onAmtChange(event: React.ChangeEvent<HTMLInputElement>): void {
-    if (event.target.value === "") {
-      return;
-    }
     setAmt(event.target.value);
   }
 
   function onPriceChange(event: React.ChangeEvent<HTMLInputElement>): void {
-    if (event.target.value === "") {
-      return;
-    }
     setPrice(event.target.value);
   }