Add test comments

rush-plugins/rush-build-graph-plugin/src/test/GraphParser.test.ts

@@ -39,6 +39,7 @@ const graphParser: GraphParser = new GraphParser({
   terminal: { writeErrorLine: jest.fn(), writeLine: jest.fn() }
 } as unknown as ILogger);
 
+// This checks the test repo output to ensure that the command succeeds and the graph is built correctly
 describe('--drop-graph integration process', () => {
   beforeAll(async () => {
     if (procOut.error) {
@@ -54,6 +55,7 @@ describe('--drop-graph integration process', () => {
   });
 });
 
+// These run unit tests on the checked in test-operation-map.json file, which mimics what rush passes in
 describe(GraphParser.name, () => {
   it('should fail if the input schema is invalid', () => {
     const operations = JSON.parse(JSON.stringify(testData.OperationMap));
@@ -77,6 +79,7 @@ describe(GraphParser.name, () => {
   });
 });
 
+// These check the graph.json file that was generated by the integration test and unit tests the validator on it
 describe('validateGraph', () => {
   it('should validate graph.json', () => {
     const isValid: boolean = graphParser.validateGraph(exampleGraph);