chore: incorporate review comments

Signed-off-by: Kumar Mallikarjuna <[email protected]>

keps/0009-cel-assertions.md

@@ -1,7 +1,7 @@
 ---
 kep-number: 9
-short-desc: This KEP discusses adding CEL-based assertions to Kuttl
-title: CEL Assertions
+short-desc: This KEP discusses adding expression-based assertions to Kuttl
+title: Expression-Based Assertions
 authors:
     - "@kumar-mallikarjuna"
 owners:
@@ -12,12 +12,11 @@ last-updated: 2024-09-23
 status: provisional
 ---
 
-# CEL Assertions
+# Expression-Based Assertions
 
 ## Summary
 
-Add Common Expression Language (CEL) support for Kuttl assertions. This would extend Kuttl's ability to perform
-assertions based on complex expressions that are currently not possible with the existing syntax.
+Add expression-based assertions to Kuttl. This can be achieved by integrating support for languages such as Common Expression Language (CEL). This would extend Kuttl's ability to perform assertions based on complex expressions that are currently not possible with the existing syntax.
 
 ## Motivation
 
@@ -46,37 +45,36 @@ evaluation and more flexible assertions.
 1. Reading non-Kubernetes resources for assertions.
 2. Reading resources from multiple clusters for assertions.
 
+> **Note:** These goals are not in the scope of the first development of this feature but should be targetted in its later phases.
+
 ## Proposal
 
 ### CRD Changes
 
 ```yaml
 apiVersion: kuttl.dev/v1beta1
 kind: TestAssert
-celAssert:
-  resources:
-  - apiVersion: apps/v1
+resourceRefs:
+    - apiVersion: apps/v1
       kind: Deployment
       name: coredns
       namespace: kube-system
-      id: resource1
-  - apiVersion: apps/v1
+      ref: coredns_deployment
+    - apiVersion: apps/v1
       kind: Deployment
       name: metrics-server
       namespace: kube-system
-      id: resource2
-
-  # Success if any expression evaluates to true
-  any:
-  - expression: "resource1.status.readyReplicas > 1"
-  - expression: ...
-  - ...
-
-  # Success only if all expressions evaluate to true
-  all:
-  - expression: "resource2.status.readyReplicas > 0"
-  - expression: ...
-  - ...
+      ref: metrics_server
+# Success if any expression evaluates to true
+assertAny:
+    - celExpr: "coredns_deployment.status.readyReplicas > 1"
+    - celExpr: ...
+    - ...
+# Success only if all expressions evaluate to true
+assertAll:
+    - celExpr: "metrics_server.status.readyReplicas > 0"
+    - celExpr: ...
+    - ...
 ```
 
 ### Implementation
@@ -85,7 +83,7 @@ At a high level, we would use the [github.com/google/cel-go/cel](https://github.
 
 ```go
 func EvaluateExpression(resources...*unstructured.Unstructured)(ref.Val, error) {
-    env, err: = cel.NewEnv(
+    env, err := cel.NewEnv(
         cel.Variable("<id1>", cel.MapType(cel.StringType, cel.DynType)),
         cel.Variable("<id2>", cel.MapType(cel.StringType, cel.DynType)),
         ...
@@ -94,17 +92,17 @@ func EvaluateExpression(resources...*unstructured.Unstructured)(ref.Val, error)
         return fmt.Errorf("failed to create environment: %w", err)
     }
 
-    ast, issues: = env.Compile(`<expression>`)
+    ast, issues := env.Compile(`<expression>`)
     if issues != nil && issues.Err() != nil {
         return fmt.Errorf("type-check error: %s", issues.Err())
     }
 
-    prg, err: = env.Program(ast)
+    prg, err := env.Program(ast)
     if err != nil {
         return fmt.Errorf("program construction error: %w", err)
     }
 
-    out, _, err: = prg.Eval(map[string] interface {} {
+    out, _, err := prg.Eval(map[string] interface {} {
         "<id1>": resources[0].Object,
         "<id2>": resources[1].Object,
         ...