Use length of tag nam rather than hard code length of gql for parsing… (#1326)

Use length of tag nam rather than hard code length of gql for parsing offset

Author: rlarcher

CHANGELOG.md

@@ -19,6 +19,7 @@
 - `apollo-graphql`
   - <First `apollo-graphql` related entry goes here>
 - `apollo-language-server`
+  - Use offset equal to length of tagname when parsing JS documents[#1050](https://github.com/apollographql/apollo-tooling/issues/1050)
   - Allow template literal placeholders that span multiple rows[#1299](https://github.com/apollographql/apollo-tooling/pull/1299)
 - `apollo-tools`
   - <First `apollo-tools` related entry goes here>

packages/apollo-language-server/src/__tests__/document.test.ts

@@ -66,5 +66,32 @@ describe("extractGraphQLDocuments", () => {
       expect(documents[0].syntaxErrors.length).toBe(0);
       expect(documents[0].ast.definitions.length).toBe(2);
     });
+
+    it("works with a custom tagname", () => {
+      const textDocument = mockTextDocument(`
+      gqltag\`
+        {
+          hero {
+            ...Hero_character
+          }
+        }
+
+        \${Hero.fragments.character}
+
+        {
+          reviews(episode: NEWHOPE) {
+            ...ReviewList_reviews
+          }
+        }
+
+        \${ReviewList.fragments.reviews}
+      \`
+    `);
+      const documents = extractGraphQLDocuments(textDocument, "gqltag");
+
+      expect(documents.length).toEqual(1);
+      expect(documents[0].syntaxErrors.length).toBe(0);
+      expect(documents[0].ast.definitions.length).toBe(2);
+    });
   });
 });

packages/apollo-language-server/src/document.ts

@@ -86,7 +86,7 @@ function extractGraphQLDocumentsFromJSTemplateLiterals(
   let result;
   while ((result = regExp.exec(text)) !== null) {
     const contents = replacePlaceholdersWithWhiteSpace(result[1]);
-    const position = document.positionAt(result.index + 4);
+    const position = document.positionAt(result.index + (tagName.length + 1));
     const locationOffset: SourceLocation = {
       line: position.line + 1,
       column: position.character + 1