fix: prevent GraphQL scalar/union from inheriting a later type's fields and line range

understand-anything-plugin/packages/core/src/__tests__/parsers.test.ts

@@ -353,6 +353,53 @@ type Mutation {
     const result = parser.analyzeFile("schema.graphql", content);
     expect(result.definitions!.some(d => d.name === "Role" && d.kind === "enum")).toBe(true);
   });
+
+  it("does not let a scalar inherit a following type's fields or line range", () => {
+    // Arrange — a custom scalar declared above an object type (a ubiquitous
+    // pattern, e.g. `scalar DateTime`). scalar has no brace body of its own.
+    const content = `scalar DateTime
+
+type User {
+  id: ID!
+  name: String!
+}`;
+
+    // Act
+    const result = parser.analyzeFile("schema.graphql", content);
+
+    // Assert — the scalar is body-less: no stolen fields, single-line range.
+    const scalar = result.definitions!.find(d => d.name === "DateTime");
+    expect(scalar).toMatchObject({ kind: "scalar", lineRange: [1, 1] });
+    expect(scalar!.fields).toEqual([]);
+
+    // The following type keeps its own fields and range.
+    const user = result.definitions!.find(d => d.name === "User");
+    expect(user).toMatchObject({ kind: "type", lineRange: [3, 6] });
+    expect(user!.fields).toEqual(["id", "name"]);
+  });
+
+  it("does not let a union inherit a following type's fields or line range", () => {
+    // Arrange — a union declared above an object type. union has no brace body.
+    const content = `union SearchResult = User | Post
+
+type Post {
+  id: ID!
+  title: String!
+}`;
+
+    // Act
+    const result = parser.analyzeFile("schema.graphql", content);
+
+    // Assert — the union is body-less: no stolen fields, single-line range.
+    const union = result.definitions!.find(d => d.name === "SearchResult");
+    expect(union).toMatchObject({ kind: "union", lineRange: [1, 1] });
+    expect(union!.fields).toEqual([]);
+
+    // The following type is unaffected.
+    const post = result.definitions!.find(d => d.name === "Post");
+    expect(post).toMatchObject({ kind: "type", lineRange: [3, 6] });
+    expect(post!.fields).toEqual(["id", "title"]);
+  });
 });
 
 describe("ProtobufParser", () => {

understand-anything-plugin/packages/core/src/plugins/parsers/graphql-parser.ts

@@ -34,12 +34,18 @@ export class GraphQLParser implements AnalyzerPlugin {
       if (name === "Query" || name === "Mutation" || name === "Subscription") continue;
       const startLine = content.slice(0, match.index).split("\n").length;
 
+      // scalar and union have no brace-delimited body. Without this guard the
+      // logic below would scan forward and capture the fields and closing brace
+      // of a later braced definition — e.g. `scalar DateTime` declared above a
+      // `type` would inherit that type's fields and line range.
+      const hasBody = kind !== "scalar" && kind !== "union";
+
       // Extract fields (for type/input/interface/enum)
-      const fields = this.extractFields(content, match.index);
+      const fields = hasBody ? this.extractFields(content, match.index) : [];
 
       // Find closing brace
       const afterMatch = content.slice(match.index);
-      const closeBrace = afterMatch.indexOf("}");
+      const closeBrace = hasBody ? afterMatch.indexOf("}") : -1;
       const endLine = closeBrace !== -1
         ? content.slice(0, match.index + closeBrace + 1).split("\n").length
         : startLine;