fix: default Content-Type to x-www-form-urlencoded when importing curl POST with body (#5040)

fix: handle missing Content-Type when importing curl POST

When importing a curl POST request with a body and no explicit
Content-Type, default to `application/x-www-form-urlencoded`
to match curl's behavior.

Reference: https://everything.curl.dev/http/post/content-type.html

packages/hoppscotch-common/src/helpers/curl/curlparser.ts

@@ -132,7 +132,16 @@ export const parseCurlCommand = (curlCommand: string) => {
     danglingParams = [...danglingParams, ...newQueries.danglingParams]
     hasBodyBeenParsed = true
   } else if (
-    rawContentType.includes("application/x-www-form-urlencoded") &&
+    (rawContentType.includes("application/x-www-form-urlencoded") ||
+      /**
+       * When using the -d option with curl for a POST operation,
+       * curl includes a default header: Content-Type: application/x-www-form-urlencoded.
+       * https://everything.curl.dev/http/post/content-type.html
+       */
+      (!rawContentType &&
+        method === "POST" &&
+        rawData &&
+        rawData.length > 0)) &&
     !!pairs &&
     Array.isArray(rawData)
   ) {