chore: add lint rule to block toMatchSnapshot usage (#28091)

Issue number: N/A

---------

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issue. -->

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etc). Submit multiple pull requests if needed. -->

## What is the current behavior?
<!-- Please describe the current behavior that you are modifying. -->

In addition to migrating away from `toMatchSnapshot` as found in PRs
such as https://github.com/ionic-team/ionic-framework/pull/28083, I
think it would be valuable to have a lint rule to prevent developers
from accidentally using this API in the future.

## What is the new behavior?
<!-- Please describe the behavior or changes that are being added by
this PR. -->

- Adds a lint rule which errors if `toMatchSnapshot` is being used in
`*.e2e.ts` files.

## Does this introduce a breaking change?

- [ ] Yes
- [x] No

<!-- If this introduces a breaking change, please describe the impact
and migration path for existing applications below. -->


## Other information

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screenshots of how the component looks before and after the change. -->

~Note: This PR's lint step will continue to fail until the remaining
`toHaveScreenshot` migration PRs have been merged. Do note merge this PR
until that has been completed.~ All set!

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Co-authored-by: Brandy Carney <brandyscarney@users.noreply.github.com>

core/.eslintrc.js

@@ -46,7 +46,8 @@ module.exports = {
     {
       "files": ["*.e2e.ts"],
       "rules": {
-        "custom-rules/await-playwright-promise-assertion": "error"
+        "custom-rules/await-playwright-promise-assertion": "error",
+        "custom-rules/no-playwright-to-match-snapshot-assertion": "error"
       }
     }
   ]

core/custom-rules/index.js

@@ -1,6 +1,7 @@
 module.exports = {
   rules: {
     'no-component-on-ready-method': require('./no-component-on-ready-method.js'),
-    'await-playwright-promise-assertion': require('./await-playwright-promise-assertion.js')
+    'await-playwright-promise-assertion': require('./await-playwright-promise-assertion.js'),
+    'no-playwright-to-match-snapshot-assertion': require('./no-playwright-to-match-snapshot-assertion.js')
   }
 }

core/custom-rules/no-playwright-to-match-snapshot-assertion.js

@@ -0,0 +1,29 @@
+module.exports = {
+  meta: {
+    messages: {
+      noPlaywrightToMatchSnapshotAssertion: '"toHaveScreenshot" assertions should be used in favor of "toMatchSnapshot". "toHaveScreenshot" brings file size reductions and anti-flake behaviors such as disabling animations by default.',
+    },
+  },
+  create(context) {
+    return {
+      ExpressionStatement(node) {
+        if (node.expression.callee === undefined) {
+          return;
+        }
+
+        const { property } = node.expression.callee;
+
+        /**
+         * Check to see if toMatchSnapshot is being used
+         */
+        if (
+          property !== undefined &&
+          property.type === 'Identifier' &&
+          property.name === 'toMatchSnapshot'
+        ) {
+          context.report({ node: node, messageId: 'noPlaywrightToMatchSnapshotAssertion' });
+        }
+      }
+    }
+  }
+};

core/playwright.config.ts

@@ -55,9 +55,6 @@ const config: PlaywrightTestConfig = {
     timeout: 5000,
     toHaveScreenshot: {
       threshold: 0.1
-    },
-    toMatchSnapshot: {
-      threshold: 0.1
     }
   },
   /* Fail the build on CI if you accidentally left test.only in the source code. */