From 8b72f3515efdf9a47b3957e4273d8d8c266f8dff Mon Sep 17 00:00:00 2001
From: Srini Maddineni <maddinenisri@gmail.com>
Date: Sat, 11 Mar 2023 13:44:51 -0500
Subject: [PATCH] let user function invoke before event skip due to not
 matching content filters

---
 src/filters/index.js            | 8 +++++++-
 test/unit/filters/index.test.js | 6 +++++-
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/src/filters/index.js b/src/filters/index.js
index 9d6b05cd..8f3bea89 100644
--- a/src/filters/index.js
+++ b/src/filters/index.js
@@ -22,7 +22,13 @@ export const prefilterOnEventTypes = (rules) =>
 export const filterOnContent = (rule, uow) => {
   /* istanbul ignore else */
   if (rule.filters) {
-    return rule.filters.reduce((a, c) => a && c(uow, rule), true);
+    const isSuccess = rule.filters.reduce((a, c) => a && c(uow, rule), true);
+    // Invoke custom function incase of filter conditions are not statisfied
+    // For example to create cloudwatch metric in case of failure
+    if (!isSuccess && rule.errorFilter) {
+      rule.errorFilter(uow);
+    }
+    return isSuccess;
   } else {
     return true;
   }
diff --git a/test/unit/filters/index.test.js b/test/unit/filters/index.test.js
index 2dd0eb40..cc93ce06 100644
--- a/test/unit/filters/index.test.js
+++ b/test/unit/filters/index.test.js
@@ -64,16 +64,20 @@ describe('filters/index.js', () => {
   });
 
   it('should filter on compound content', () => {
+    const errorFilter = (uow) => { uow.isSkipped = true; };
     const rule = {
       filters: [
         (uow, r) => uow.event.tags.f1 === r.value,
         (uow, r) => uow.event.tags.f2 === r.value,
       ],
+      errorFilter,
       value: 'v1',
     };
 
     expect(filterOnContent(rule, { event: { tags: { f1: 'v1', f2: 'v1' } } })).to.be.true;
-    expect(filterOnContent(rule, { event: { tags: { f1: 'v2', f2: 'v1' } } })).to.be.false;
+    const event = { event: { tags: { f1: 'v2', f2: 'v1' } } };
+    expect(filterOnContent(rule, event)).to.be.false;
+    expect(event.isSkipped).to.be.true;
     expect(filterOnContent(rule, { event: { tags: { f1: 'v1', f2: 'v2' } } })).to.be.false;
   });
 });