[Agent Packages] Extend 'contains' helper to work on strings (#102786) (

#102943)

* Extend 'contains' helper to work on strings

* remove stray import

Co-authored-by: Andrew Stucki <andrew.stucki@elastic.co>

x-pack/plugins/fleet/server/services/epm/agent/agent.test.ts

@@ -129,6 +129,13 @@ processors:
 password: {{password}}
 {{#if password}}
 hidden_password: {{password}}
+{{/if}}
+      `;
+    const streamTemplateWithString = `
+{{#if (contains ".pcap" file)}}
+pcap: true
+{{else}}
+pcap: false
 {{/if}}
       `;
 
@@ -168,6 +175,28 @@ hidden_password: {{password}}
         tags: ['foo', 'bar'],
       });
     });
+
+    it('should support strings', () => {
+      const vars = {
+        file: { value: 'foo.pcap' },
+      };
+
+      const output = compileTemplate(vars, streamTemplateWithString);
+      expect(output).toEqual({
+        pcap: true,
+      });
+    });
+
+    it('should support strings with no match', () => {
+      const vars = {
+        file: { value: 'file' },
+      };
+
+      const output = compileTemplate(vars, streamTemplateWithString);
+      expect(output).toEqual({
+        pcap: false,
+      });
+    });
   });
 
   it('should support optional yaml values at root level', () => {

x-pack/plugins/fleet/server/services/epm/agent/agent.ts

@@ -111,11 +111,12 @@ function buildTemplateVariables(variables: PackagePolicyConfigRecord, templateSt
   return { vars, yamlValues };
 }
 
-function containsHelper(this: any, item: string, list: string[], options: any) {
-  if (Array.isArray(list) && list.includes(item)) {
+function containsHelper(this: any, item: string, check: string | string[], options: any) {
+  if ((Array.isArray(check) || typeof check === 'string') && check.includes(item)) {
     if (options && options.fn) {
       return options.fn(this);
     }
+    return true;
   }
   return '';
 }