feat: set lint --max-warnings to -1

Signed-off-by: Paul Schultz <pschultz@pobox.com>

.changeset/tall-meals-prove.md

@@ -0,0 +1,7 @@
+---
+'@backstage/cli': minor
+---
+
+**BREAKING**: ESLint warnings no longer trigger system exit codes like errors do.
+
+Set the max number of warnings to `-1` during linting to enable the gradual adoption of new ESLint rules. To restore the previous behavior, include the `--max-warnings 0` flag in the `backstage-cli <repo|package> lint` command.

docs/tooling/cli/03-commands.md

@@ -189,7 +189,7 @@ Lint a package
 Options:
   --format <format>        Lint report output format (default: "eslint-formatter-friendly")
   --fix                    Attempt to automatically fix violations
-  --max-warnings <number>  Fail if more than this number of warnings. -1 allows warnings. (default: 0)
+  --max-warnings <number>  Fail if more than this number of warnings. -1 allows warnings. (default: -1)
 ```
 
 ## package test

packages/cli/config/eslint-factory.js

@@ -95,7 +95,7 @@ function createConfig(dir, extraConfig = {}) {
       '@typescript-eslint/no-unused-expressions': 'error',
       '@typescript-eslint/consistent-type-assertions': 'error',
       '@typescript-eslint/no-unused-vars': [
-        'warn',
+        'error',
         {
           vars: 'all',
           args: 'after-used',
@@ -173,7 +173,7 @@ function createConfig(dir, extraConfig = {}) {
           'no-unused-vars': 'off',
           'unused-imports/no-unused-imports': 'error',
           'unused-imports/no-unused-vars': [
-            'warn',
+            'error',
             {
               vars: 'all',
               varsIgnorePattern: '^_',

packages/cli/src/commands/index.ts

@@ -129,7 +129,7 @@ export function registerScriptCommand(program: Command) {
     .option('--fix', 'Attempt to automatically fix violations')
     .option(
       '--max-warnings <number>',
-      'Fail if more than this number of warnings. -1 allows warnings. (default: 0)',
+      'Fail if more than this number of warnings. -1 allows warnings. (default: -1)',
     )
     .description('Lint a package')
     .action(lazy(() => import('./lint'), 'default'));

packages/cli/src/commands/lint.ts

@@ -30,7 +30,7 @@ export default async (directories: string[], opts: OptionValues) => {
     directories.length ? directories : ['.'],
   );
 
-  const maxWarnings = opts.maxWarnings ?? 0;
+  const maxWarnings = opts.maxWarnings ?? -1;
   const ignoreWarnings = +maxWarnings === -1;
 
   const failed =