fix: reverts the defaulting behavior of 1 eth to usdc (#3465)

cypress/integration/swap.test.ts

@@ -3,11 +3,11 @@ describe('Swap', () => {
     cy.visit('/swap')
   })
 
-  it('starts with an ETH/USDC swap and quotes it', () => {
-    cy.get('#swap-currency-input .token-amount-input').should('have.value', '1')
+  it('starts with ETH selected by default', () => {
+    cy.get('#swap-currency-input .token-amount-input').should('have.value', '')
     cy.get('#swap-currency-input .token-symbol-container').should('contain.text', 'ETH')
-    cy.get('#swap-currency-output .token-amount-input').should('not.have.value', '')
-    cy.get('#swap-currency-output .token-symbol-container').should('contain.text', 'USDC')
+    cy.get('#swap-currency-output .token-amount-input').should('not.have.value')
+    cy.get('#swap-currency-output .token-symbol-container').should('contain.text', 'Select a token')
   })
 
   it('can enter an amount into input', () => {

src/state/swap/hooks.test.ts

@@ -27,8 +27,8 @@ describe('hooks', () => {
         queryParametersToSwapState(parse('?outputCurrency=invalid', { parseArrays: false, ignoreQueryPrefix: true }))
       ).toEqual({
         [Field.INPUT]: { currencyId: 'ETH' },
-        [Field.OUTPUT]: { currencyId: 'USDC' },
-        typedValue: '1',
+        [Field.OUTPUT]: { currencyId: null },
+        typedValue: '',
         independentField: Field.INPUT,
         recipient: null,
       })

src/state/swap/hooks.tsx

@@ -219,14 +219,12 @@ function validatedRecipient(recipient: any): string | null {
 export function queryParametersToSwapState(parsedQs: ParsedQs): SwapState {
   let inputCurrency = parseCurrencyFromURLParameter(parsedQs.inputCurrency)
   let outputCurrency = parseCurrencyFromURLParameter(parsedQs.outputCurrency)
-  let typedValue = parseTokenAmountURLParameter(parsedQs.exactAmount)
+  const typedValue = parseTokenAmountURLParameter(parsedQs.exactAmount)
   const independentField = parseIndependentFieldURLParameter(parsedQs.exactField)
 
   if (inputCurrency === '' && outputCurrency === '' && typedValue === '' && independentField === Field.INPUT) {
-    // Defaults to 1 ETH -> USDC
+    // Defaults to having the native currency selected
     inputCurrency = 'ETH'
-    outputCurrency = 'USDC'
-    typedValue = '1'
   } else if (inputCurrency === outputCurrency) {
     // clear output if identical
     outputCurrency = ''