clean up parseCurrencyFromURLParameter

src/state/swap/hooks.test.ts

@@ -25,8 +25,8 @@ describe('hooks', () => {
       expect(
         queryParametersToSwapState(parse('?outputCurrency=invalid', { parseArrays: false, ignoreQueryPrefix: true }))
       ).toEqual({
-        [Field.INPUT]: { currencyId: '' },
-        [Field.OUTPUT]: { currencyId: 'ETH' },
+        [Field.INPUT]: { currencyId: 'ETH' },
+        [Field.OUTPUT]: { currencyId: '' },
         typedValue: '',
         independentField: Field.INPUT,
         recipient: null,

src/state/swap/hooks.ts

@@ -217,9 +217,8 @@ function parseCurrencyFromURLParameter(urlParam: any): string {
     const valid = isAddress(urlParam)
     if (valid) return valid
     if (urlParam.toUpperCase() === 'ETH') return 'ETH'
-    if (valid === false) return 'ETH'
   }
-  return 'ETH' ?? ''
+  return ''
 }
 
 function parseTokenAmountURLParameter(urlParam: any): string {
@@ -244,12 +243,12 @@ function validatedRecipient(recipient: any): string | null {
 export function queryParametersToSwapState(parsedQs: ParsedQs): SwapState {
   let inputCurrency = parseCurrencyFromURLParameter(parsedQs.inputCurrency)
   let outputCurrency = parseCurrencyFromURLParameter(parsedQs.outputCurrency)
-  if (inputCurrency === outputCurrency) {
-    if (typeof parsedQs.outputCurrency === 'string') {
-      inputCurrency = ''
-    } else {
-      outputCurrency = ''
-    }
+  if (inputCurrency === '' && outputCurrency === '') {
+    // default to ETH input
+    inputCurrency = 'ETH'
+  } else if (inputCurrency === outputCurrency) {
+    // clear output if identical
+    outputCurrency = ''
   }
 
   const recipient = validatedRecipient(parsedQs.recipient)