added test for the handling

Author: EmilioTR

cypress/e2e/queryLocation-test.cy.js

@@ -0,0 +1,20 @@
+describe("query location tests", () => {
+
+    // Errors with the correct message should be thrown
+    it("queryLocation that does not end on rq", () => {
+        cy.visit("/");
+        cy.contains("For testing only").click();
+        cy.contains("Average value - queryLocation without rq").click();
+
+        cy.contains("Invalid query location.").should("exist");
+      });
+
+      it("wrong queryLocation that does not exist, correct file ending", () => {
+        cy.visit("/");
+        cy.contains("For testing only").click();
+        cy.contains("Average value - unexisting queryLocation (ends in .rq)").click();
+
+        cy.contains("Empty query text. Check your query and location.").should("exist");
+      });
+  });
+  

src/dataProvider/SparqlDataProvider.js

@@ -113,7 +113,7 @@ async function buildQueryText(query) {
       throw new Error("Invalid query location.")
     }
     if (rawText === null || rawText === '' ) {
-      throw new Error("Empty query text.")
+      throw new Error("Empty query text. Check your query and location.")
     }
 
     if (query.variableValues) {