handle noFileSelected case

apps/vyper/src/app/app.tsx

@@ -38,7 +38,8 @@ const App: React.FC = () => {
     async function start() {
       try {
         await remixClient.loaded()
-        remixClient.onFileChange(name => setContract(name))
+        remixClient.onFileChange(name => setContract(name))        
+        remixClient.onNoFileSelected(() => setContract(''))
         const name = await remixClient.getContractName()
         setContract(name)
       } catch (err) {

apps/vyper/src/app/components/CompilerButton.tsx

@@ -31,8 +31,8 @@ function CompilerButton({ contract, setOutput, compilerUrl }: Props) {
       let _contract
       try {
         _contract = await remixClient.getContract()
-      } catch (e) {
-        setOutput('', { status: 'failed', message: err.message})
+      } catch (e: any) {
+        setOutput('', { status: 'failed', message: e.message})
         return
       }      
       remixClient.changeStatus({
@@ -43,19 +43,21 @@ function CompilerButton({ contract, setOutput, compilerUrl }: Props) {
       let output
       try {
         output = await compile(compilerUrl, _contract)
-      } catch (e) {
-        setOutput(_contract.name, { status: 'failed', message: err.message})
+      } catch (e: any) {
+        setOutput(_contract.name, { status: 'failed', message: e.message})
         return
       }      
       setOutput(_contract.name, output)
       // ERROR
       if (isCompilationError(output)) {
         const line = output.line
-        const lineColumnPos = {
-          start: { line: line - 1 },
-          end: { line: line - 1 }
+        if (line) {
+          const lineColumnPos = {
+            start: { line: line - 1 },
+            end: { line: line - 1 }
+          }
+          remixClient.highlight(lineColumnPos as any, _contract.name, '#e0b4b4')
         }
-        remixClient.highlight(lineColumnPos as any, _contract.name, '#e0b4b4')
         throw new Error(output.message)
       }
       // SUCCESS

apps/vyper/src/app/utils/compiler.tsx

@@ -18,8 +18,8 @@ export interface VyperCompilationResult {
 
 export interface VyperCompilationError {
   status: 'failed'
-  column: number
-  line: number
+  column?: number
+  line?: number
   message: string
 }
 

apps/vyper/src/app/utils/remix-client.tsx

@@ -14,11 +14,17 @@ export class RemixClient extends PluginClient {
   /** Emit an event when file changed */
   async onFileChange(cb: (contract: string) => any) {
     this.client.on('fileManager', 'currentFileChanged', async (name: string) => {
-      if (!name) return
       cb(name)
     })
   }
 
+  /** Emit an event when file changed */
+  async onNoFileSelected(cb: () => any) {
+    this.client.on('fileManager', 'noFileSelected', async () => {
+      cb()
+    })
+  }
+
   /** Load Ballot contract example into the file manager */
   async loadContract({name, content}: Contract) {
     try {