fix(Nag Reports): compliance reports not generated for stacks with no…

… relevant resources (#723)

src/nag-pack.ts

@@ -127,12 +127,13 @@ export abstract class NagPack implements IAspect {
     const ruleId = `${this.packName}-${ruleSuffix}`;
     try {
       const ruleCompliance = params.rule(params.node);
-      if (
-        this.reports === true &&
-        ruleCompliance === NagRuleCompliance.COMPLIANT
-      ) {
-        this.writeToStackComplianceReport(params, ruleId, ruleCompliance);
-      } else if (this.isNonCompliant(ruleCompliance)) {
+      if (this.reports === true) {
+        this.initializeStackReport(params);
+        if (ruleCompliance === NagRuleCompliance.COMPLIANT) {
+          this.writeToStackComplianceReport(params, ruleId, ruleCompliance);
+        }
+      }
+      if (this.isNonCompliant(ruleCompliance)) {
         const findings = this.asFindings(ruleCompliance);
         for (const findingId of findings) {
           const suppressionReason = this.ignoreRule(
@@ -249,7 +250,7 @@ export abstract class NagPack implements IAspect {
   }
 
   /**
-   * Write a line to the rule packs compliance report for the resource's Stack
+   * Write a line to the rule pack's compliance report for the resource's Stack
    * @param params The @IApplyRule interface with rule details.
    * @param ruleId The id of the rule.
    * @param compliance The compliance status of the rule.
@@ -270,20 +271,33 @@ export abstract class NagPack implements IAspect {
       compliance,
       explanation
     );
-    let outDir = App.of(params.node)?.outdir;
+    const outDir = App.of(params.node)?.outdir;
     const stackName = params.node.stack.nested
       ? Names.uniqueId(params.node.stack)
       : params.node.stack.stackName;
     const fileName = `${this.packName}-${stackName}-NagReport.csv`;
     const filePath = join(outDir ? outDir : '', fileName);
+    appendFileSync(filePath, line);
+  }
+
+  /**
+   * Initialize the report for the rule pack's compliance report for the resource's Stack if it doesn't exist
+   * @param params
+   */
+  protected initializeStackReport(params: IApplyRule): void {
+    const stackName = params.node.stack.nested
+      ? Names.uniqueId(params.node.stack)
+      : params.node.stack.stackName;
+    const fileName = `${this.packName}-${stackName}-NagReport.csv`;
     if (!this.reportStacks.includes(fileName)) {
+      const outDir = App.of(params.node)?.outdir;
+      const filePath = join(outDir ? outDir : '', fileName);
       this.reportStacks.push(fileName);
       writeFileSync(
         filePath,
         'Rule ID,Resource ID,Compliance,Exception Reason,Rule Level,Rule Info\n'
       );
     }
-    appendFileSync(filePath, line);
   }
 
   /**

test/Engine.test.ts

@@ -915,7 +915,9 @@ describe('Report system', () => {
             explanation: 'bar.',
             level: NagMessageLevel.ERROR,
             rule: function (node2: CfnResource): NagRuleCompliance {
-              if (node2.cfnResourceType !== 'Error') {
+              if (node2.cfnResourceType === 'N/A') {
+                return NagRuleCompliance.NOT_APPLICABLE;
+              } else if (node2.cfnResourceType !== 'Error') {
                 return compliance;
               }
               throw Error('foobar');
@@ -958,6 +960,18 @@ describe('Report system', () => {
     app.synth();
     expect(pack.readReportStacks.length).toEqual(2);
   });
+  test('Reports are initialized for stacks with no relevant resources', () => {
+    const app = new App();
+    const stack = new Stack(app, 'Stack1');
+    const pack = new TestPack();
+    Aspects.of(app).add(pack);
+    new CfnResource(stack, 'rNAResource', {
+      type: 'N/A',
+    });
+    app.synth();
+    expect(pack.readReportStacks.length).toEqual(1);
+    expect(pack.lines.length).toBe(0);
+  });
   test('Nested Stack reports do not contain tokens in names', () => {
     const app = new App();
     const parent = new Stack(app, 'Parent');