feat(rules): add no-interpolation-inline-snapshot rule

docs/rules/no-interpolation-inline-snapshot.md

@@ -0,0 +1,54 @@
+# No string interpolation inside inline snapshots (no-interpolation-inline-snapshot)
+
+Prevents the use of string interpolations within `toMatchInlineSnapshot`.
+
+## Rule Details
+
+Interpolation prevents snapshots from being updated. Instead, properties should
+be overloaded with a matcher by passing the optional `propertyMatchers` argument
+to `toMatchInlineSnapshot`.
+
+Examples of **incorrect** code for this rule:
+
+```js
+expect(something).toMatchInlineSnapshot(
+  `Object {
+    property: ${interpolated}
+  }`,
+);
+
+expect(something).toMatchInlineSnapshot(
+  { other: expect.any(Number) },
+  `Object {
+    other: Any<Number>,
+    property: ${interpolated}
+  }`,
+);
+```
+
+Examples of **correct** code for this rule:
+
+```js
+expect(something).toMatchInlineSnapshot();
+
+expect(something).toMatchInlineSnapshot(
+  `Object {
+    property: 1
+  }`,
+);
+
+expect(something).toMatchInlineSnapshot(
+  { property: expect.any(Date) },
+  `Object {
+    property: Any<Date>
+  }`,
+);
+```
+
+\*Note that this rule will not trigger if the helper function is never used even
+thought the `expect` will not execute. Rely on a rule like no-unused-vars for
+this case.
+
+## When Not To Use It
+
+Don't use this rule on non-jest test files.

src/__tests__/__snapshots__/rules.test.ts.snap

@@ -23,6 +23,7 @@ Object {
       "jest/no-hooks": "error",
       "jest/no-identical-title": "error",
       "jest/no-if": "error",
+      "jest/no-interpolation-inline-snapshot": "error",
       "jest/no-jasmine-globals": "error",
       "jest/no-jest-import": "error",
       "jest/no-large-snapshots": "error",

src/__tests__/rules.test.ts

@@ -3,7 +3,7 @@ import { resolve } from 'path';
 import plugin from '../';
 
 const ruleNames = Object.keys(plugin.rules);
-const numberOfRules = 40;
+const numberOfRules = 41;
 
 describe('rules', () => {
   it('should have a corresponding doc for each rule', () => {

src/rules/__tests__/no-interpolation-inline-snapshot.test.ts

@@ -0,0 +1,40 @@
+import { TSESLint } from '@typescript-eslint/experimental-utils';
+import resolveFrom from 'resolve-from';
+import rule from '../no-interpolation-inline-snapshot';
+
+const ruleTester = new TSESLint.RuleTester({
+  parser: resolveFrom(require.resolve('eslint'), 'espree'),
+  parserOptions: {
+    ecmaVersion: 2017,
+  },
+});
+
+ruleTester.run('no-interpolation-inline-snapshot', rule, {
+  valid: [
+    'expect(something).toMatchInlineSnapshot();',
+    'expect(something).toMatchInlineSnapshot(`No interpolation`);',
+    'expect(something).toMatchInlineSnapshot({}, `No interpolation`);',
+  ],
+  invalid: [
+    {
+      code: 'expect(something).toMatchInlineSnapshot(`${interpolated}`);',
+      errors: [
+        {
+          endColumn: 58,
+          column: 41,
+          messageId: 'noInterpolation',
+        },
+      ],
+    },
+    {
+      code: 'expect(something).toMatchInlineSnapshot({}, `${interpolated}`);',
+      errors: [
+        {
+          endColumn: 62,
+          column: 45,
+          messageId: 'noInterpolation',
+        },
+      ],
+    },
+  ],
+});

src/rules/no-interpolation-inline-snapshot.ts

@@ -0,0 +1,48 @@
+import { AST_NODE_TYPES } from '@typescript-eslint/experimental-utils';
+import { createRule } from './utils';
+
+export default createRule({
+  name: __filename,
+  meta: {
+    docs: {
+      category: 'Best Practices',
+      description: 'Disallow string interpolation inside inline snapshots.',
+      recommended: false,
+    },
+    messages: {
+      noInterpolation:
+        'Do not use string interpolation inside of inline snapshots',
+    },
+    schema: [],
+    type: 'suggestion',
+  },
+  defaultOptions: [],
+  create(context) {
+    return {
+      CallExpression(node) {
+        const { callee, arguments: nodeArguments } = node;
+
+        if (
+          callee.type !== AST_NODE_TYPES.MemberExpression ||
+          callee.property.type !== AST_NODE_TYPES.Identifier ||
+          callee.property.name !== 'toMatchInlineSnapshot'
+        ) {
+          return;
+        }
+
+        // Check all since the optional 'propertyMatchers' argument might be present
+        nodeArguments.forEach(argument => {
+          if (
+            argument.type === AST_NODE_TYPES.TemplateLiteral &&
+            argument.expressions.length > 0
+          ) {
+            context.report({
+              messageId: 'noInterpolation',
+              node: argument,
+            });
+          }
+        });
+      },
+    };
+  },
+});