fix greedy 404

src/utils/errors.ts

@@ -2,6 +2,9 @@ import type { resourceType } from '../types/resources'
 
 export enum errorType {
   URL_ERROR = 'URL_ERROR',
+  NETWORK_ERROR = 'NETWORK_ERROR',
+  NOT_FOUND = 'NOT_FOUND',
+  NOT_HTML = 'NOT_HTML',
 }
 
 export class PreviewError extends Error {

src/utils/fetch.ts

@@ -1,9 +1,19 @@
-export const proxyFetch = (url: string) =>
-  fetch(`https://api.codetabs.com/v1/proxy/?quest=${url}`, undefined).then(
-    (res) => {
-      if (!res.ok) throw new Error(`Could not load ${url}`)
-      // TODO - handle 404s/pageful errors
-      // if (res.status === 404) return null
-      return res.text()
-    },
+import { PreviewError, errorType } from './errors'
+
+export async function proxyFetch(url: string) {
+  const res = await fetch(
+    `https://api.codetabs.com/v1/proxy/?quest=${url}`,
+    undefined,
   )
+
+  if (!res.ok)
+    throw new PreviewError(`Could not load ${url}`, errorType.NETWORK_ERROR)
+
+  const raw = await res.text()
+
+  if (res.status === 404 || raw.includes('<title>Not Found</title>'))
+    // Manually check for this title since Gitlab returns a 200 for non-existent files
+    throw new PreviewError(`Could not load ${url}`, errorType.NOT_FOUND)
+
+  return raw
+}

src/utils/preview.ts

@@ -1,4 +1,5 @@
 import { goto } from '$app/navigation'
+import { PreviewError, errorType } from './errors'
 import { proxyFetch } from './fetch'
 import { processCSS } from './lang/css'
 import { isHTML, processHTML, type HTMLPageData } from './lang/html'
@@ -44,8 +45,13 @@ export class Preview {
         .then(async (data) => {
           await this.loadHTML(data, htmlURL)
         })
-        .catch((error) => {
-          console.error(error)
+        .catch(() => {
+          throw new PreviewError(
+            `Could not find any valid HTML files. Tried:\n${urls.join(
+              '\n - ',
+            )}`,
+            errorType.NOT_FOUND,
+          )
         })
     } else {
       // otherwise we have to attempt to load 3 possible URLs
@@ -65,8 +71,10 @@ export class Preview {
       )
 
       if (errorTable.every((e) => e)) {
-        // TODO: only throw error if the user is attempting to load without a file path
-        // throw Error('Could not find index.html on <main> or <master> branch')
+        throw new PreviewError(
+          `Could not find any valid HTML files. Tried:\n${urls.join('\n - ')}`,
+          errorType.NOT_FOUND,
+        )
       }
     }
   }