test(type-utils): add basic tests for isTypeReadonly

[RebeccaStevens]

PR Checklist

• Addresses an existing issue
• That issue was marked as accepting prs
• Steps in CONTRIBUTING.md were taken

Overview

Add basic tests for isTypeReadonly.

Note: this PR is the base of #4417, #4419,#4421 and #4429

[nx-cloud]

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✅ Successfully ran 48 targets

• Node 16.x - nx test @typescript-eslint/eslint-plugin-tslint
• Node 16.x - nx test @typescript-eslint/eslint-plugin
• Node 14.x - nx test @typescript-eslint/eslint-plugin-tslint
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• Node 12.x - nx test @typescript-eslint/eslint-plugin
• Node 16.x - nx test @typescript-eslint/parser
• Node 16.x - nx test @typescript-eslint/type-utils
• Node 16.x - nx test @typescript-eslint/experimental-utils
• Node 16.x - nx test @typescript-eslint/scope-manager
• Node 16.x - nx test @typescript-eslint/visitor-keys
• Node 16.x - nx test @typescript-eslint/typescript-estree
• Node 16.x - nx run-many --target=build --all --parallel --exclude website --exclude website
• Node 16.x - nx prebuild @typescript-eslint/types
• Node 12.x - nx run-many --target=typecheck --all --parallel
• Node 14.x - nx test @typescript-eslint/parser
• Node 14.x - nx test @typescript-eslint/type-utils
• Node 14.x - nx test @typescript-eslint/experimental-utils
• Node 14.x - nx test @typescript-eslint/scope-manager
• Node 14.x - nx test @typescript-eslint/visitor-keys
• Node 14.x - nx test @typescript-eslint/typescript-estree
• Node 14.x - nx run-many --target=build --all --parallel --exclude website --exclude website
• Node 12.x - nx run-many --target=build --all --parallel --exclude website --exclude website
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• Node 12.x - nx test @typescript-eslint/parser
• Node 12.x - nx test @typescript-eslint/parser
• Node 12.x - nx test @typescript-eslint/type-utils
• Node 12.x - nx test @typescript-eslint/type-utils
• Node 12.x - nx test @typescript-eslint/experimental-utils
• Node 12.x - nx test @typescript-eslint/scope-manager
• Node 12.x - nx test @typescript-eslint/visitor-keys
• Node 12.x - nx test @typescript-eslint/typescript-estree
• Node 12.x - nx run-many --target=build --all --parallel --exclude website --exclude website
• Node 12.x - nx test @typescript-eslint/experimental-utils
• Node 12.x - nx test @typescript-eslint/scope-manager
• Node 12.x - nx test @typescript-eslint/visitor-keys
• Node 12.x - nx test @typescript-eslint/typescript-estree
• Node 12.x - nx run-many --target=build --all --parallel --exclude website --exclude website
• Node 12.x - nx run-many --target=build --all --parallel --exclude website --exclude website
• Node 14.x - nx prebuild @typescript-eslint/types
• Node 12.x - nx prebuild @typescript-eslint/types
• Node 12.x - nx prebuild @typescript-eslint/types
• Node 12.x - nx prebuild @typescript-eslint/types
• Node 12.x - nx prebuild @typescript-eslint/types
• Node 12.x - nx prebuild @typescript-eslint/types

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[typescript-eslint]

Thanks for the PR, @RebeccaStevens!

typescript-eslint is a 100% community driven project, and we are incredibly grateful that you are contributing to that community.

The core maintainers work on this in their personal time, so please understand that it may not be possible for them to review your work immediately.

Thanks again!

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[codecov]

Codecov Report

Merging #4416 (c7051e1) into main (e61e388) will increase coverage by 0.34%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main    #4416      +/-   ##
==========================================
+ Coverage   94.26%   94.61%   +0.34%     
==========================================
  Files         169      147      -22     
  Lines        9440     7841    -1599     
  Branches     2940     2507     -433     
==========================================
- Hits         8899     7419    -1480     
+ Misses        321      233      -88     
+ Partials      220      189      -31     

Flag	Coverage Δ
unittest	94.61% <ø> (+0.34%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
...escript-estree/src/semantic-or-syntactic-errors.ts
...gin-internal/src/rules/no-poorly-typed-ts-props.ts
...pt-estree/src/ts-estree/estree-to-ts-node-types.ts
packages/typescript-estree/src/convert.ts
packages/typescript-estree/src/node-utils.ts
...t-estree/src/create-program/useProvidedPrograms.ts
packages/typescript-estree/src/ast-converter.ts
packages/typescript-estree/src/convert-comments.ts
packages/typescript-estree/src/ts-estree/index.ts
packages/typescript-estree/src/version-check.ts
... and 12 more

[bradzacher]

thanks so much for adding this!