fix(no-deprecated-functions): make missing jest a rule error, not fatal

Author: wjhsf

src/rules/no-deprecated-functions.ts

@@ -1,29 +1,11 @@
 import { AST_NODE_TYPES, type TSESTree } from '@typescript-eslint/utils';
 import {
-  type JestVersion,
+  type EslintPluginJestRuleContext,
   createRule,
-  detectJestVersion,
+  getJestVersion,
   getNodeName,
 } from './utils';
 
-interface ContextSettings {
-  jest?: EslintPluginJestSettings;
-}
-
-interface EslintPluginJestSettings {
-  version: JestVersion | string;
-}
-
-const parseJestVersion = (rawVersion: number | string): JestVersion => {
-  if (typeof rawVersion === 'number') {
-    return rawVersion;
-  }
-
-  const [majorVersion] = rawVersion.split('.');
-
-  return parseInt(majorVersion, 10);
-};
-
 export default createRule({
   name: __filename,
   meta: {
@@ -33,17 +15,20 @@ export default createRule({
     messages: {
       deprecatedFunction:
         '`{{ deprecation }}` has been deprecated in favor of `{{ replacement }}`',
+      jestNotDetected:
+        'Unable to detect Jest version - please ensure jest package is installed, or otherwise set version explicitly',
     },
     type: 'suggestion',
     schema: [],
     fixable: 'code',
   },
   defaultOptions: [],
   create(context) {
-    const jestVersion = parseJestVersion(
-      (context.settings as ContextSettings)?.jest?.version ||
-        detectJestVersion(),
-    );
+    // If jest version is not detected, it is set to Infinity so that all possible deprecations
+    // are reported with a "jest not detected" error message
+    const jestVersion =
+      getJestVersion(context as EslintPluginJestRuleContext) || Infinity;
+    const jestNotDetected = jestVersion === Infinity;
 
     const deprecations: Record<string, string> = {
       ...(jestVersion >= 15 && {
@@ -80,13 +65,16 @@ export default createRule({
         const { callee } = node;
 
         context.report({
-          messageId: 'deprecatedFunction',
+          messageId: jestNotDetected ? 'jestNotDetected' : 'deprecatedFunction',
           data: {
             deprecation,
             replacement,
           },
           node,
           fix(fixer) {
+            if (jestNotDetected) {
+              return [];
+            }
             let [name, func] = replacement.split('.');
 
             if (callee.property.type === AST_NODE_TYPES.Literal) {

src/rules/utils/detectJestVersion.ts

@@ -1,4 +1,19 @@
 import type { JSONSchemaForNPMPackageJsonFiles } from '@schemastore/package';
+import type { RuleContext } from '@typescript-eslint/utils/ts-eslint';
+
+interface ContextSettings {
+  [key: string]: unknown;
+  jest?: EslintPluginJestSettings;
+}
+
+interface EslintPluginJestSettings {
+  version: JestVersion | string;
+}
+
+export interface EslintPluginJestRuleContext
+  extends Readonly<RuleContext<never, []>> {
+  settings: ContextSettings;
+}
 
 export type JestVersion =
   | 14
@@ -22,7 +37,25 @@ export type JestVersion =
 
 let cachedJestVersion: JestVersion | null = null;
 
-export const detectJestVersion = (): JestVersion => {
+const parseJestVersion = (rawVersion: number | string): JestVersion => {
+  if (typeof rawVersion === 'number') {
+    return rawVersion;
+  }
+
+  const [majorVersion] = rawVersion.split('.');
+
+  return parseInt(majorVersion, 10);
+};
+
+export const getContextJestVersion = (
+  context: EslintPluginJestRuleContext,
+): JestVersion | null => {
+  return context.settings.jest?.version
+    ? parseJestVersion(context.settings.jest.version)
+    : null;
+};
+
+export const detectJestVersion = (): JestVersion | null => {
   if (cachedJestVersion) {
     return cachedJestVersion;
   }
@@ -35,13 +68,15 @@ export const detectJestVersion = (): JestVersion => {
       require(jestPath) as JSONSchemaForNPMPackageJsonFiles;
 
     if (jestPackageJson.version) {
-      const [majorVersion] = jestPackageJson.version.split('.');
-
-      return (cachedJestVersion = parseInt(majorVersion, 10));
+      return (cachedJestVersion = parseJestVersion(jestPackageJson.version));
     }
   } catch {}
 
-  throw new Error(
-    'Unable to detect Jest version - please ensure jest package is installed, or otherwise set version explicitly',
-  );
+  return null;
+};
+
+export const getJestVersion = (
+  context: EslintPluginJestRuleContext,
+): JestVersion | null => {
+  return getContextJestVersion(context) || detectJestVersion();
 };