Automated testing usually gets filed under "quality" — a way to ship fewer bugs. That's true, but it undersells what good test coverage does for security. On the Salesforce platform especially, the line between a functional test and a security test is thinner than it looks.
Apex deployments to production require at least 75% code coverage. Most teams treat that as a hurdle to clear. A better framing: you're already obligated to write tests, so make them earn their keep by asserting on security-relevant behavior, not just code paths.
The most valuable security tests verify that the right users can't do the wrong things. With System.runAs(), you can execute Apex as a specific user and assert that access is correctly denied:
@isTest
static void guestCannotReadSensitiveAccounts() {
User guest = [SELECT Id FROM User WHERE Profile.Name = 'Guest' LIMIT 1];
System.runAs(guest) {
Test.startTest();
List<Account> rows = AccountService.getSensitiveAccounts();
Test.stopTest();
System.assertEquals(0, rows.size(),
'Guest user must not see sensitive accounts');
}
}A test like this turns "we think the sharing model is correct" into "the build fails if it isn't." That's the difference between a hope and a control.
Security issues love to come back. A field gets unmarked as encrypted, a permission set is widened, an Apex method drops its FLS check during a refactor. Without tests, these slip through review and reach production silently. With assertions wired into CI, the regression is caught the moment it's introduced.
A vulnerability you fixed last quarter is only fixed if something stops it from coming back.
Tests that only run when someone remembers to run them aren't a control. Wire your Apex and LWC tests into a CI/CD pipeline so every change is validated automatically before it can be deployed. Add static analysis and security scanning to the same pipeline, and you've built a gate that's hard to bypass under deadline pressure — which is exactly when shortcuts happen.
System.runAs() tests for access-control boundariesTeams that invest here move faster, not slower. When the pipeline guarantees that access controls still hold, you can refactor and ship with confidence instead of fear. Security stops being the thing that blocks releases and becomes part of how releases happen.
Echo helps teams build automated test suites that double as security controls and wire them into delivery. Reach out if that's where you want to get to.