‼️ cli: @types/babel__traverse@7.18.3 breaks builds

[mrgrain]

Status: RESOLVED

Projects using TypeScript <4.2 (like the ones created with cdk init are failing to compile due to a transitive dependency introducing a breaking change. This issue does not affect you if you are using a recent TypeScript version.

Possible Solutions

Any of the following options will work around this issue:

• Pin @types/babel__traverse to 7.18.2 in devDependencies
  package.json

{
  "devDependencies": {
    "@types/babel__traverse": "7.18.2"
  }
}

• Upgrade the TypeScript version to TS >=4.2

• Create new apps with a AWS CDK CLI of version >=2.52.1 or >=1.81.1 or projen

Describe the bug

A recent release of @types/babel__traverse (7.18.3) updated the minimum typescript version to 4.2. If you have CDK apps created with cdk init and not upgraded the TypeScript version, the build will fail.

$npm ls @types/babel__traverse
cdk-app@0.1.0 
├── @types/babel__traverse@7.18.2
├─┬ jest@27.5.1
│ └─┬ @jest/core@27.5.1
│   └─┬ jest-snapshot@27.5.1
│     └── @types/babel__traverse@7.18.2 deduped
└─┬ ts-jest@27.1.5
  └─┬ babel-jest@27.5.1
    ├─┬ @types/babel__core@7.1.20
    │ └── @types/babel__traverse@7.18.2 deduped
    └─┬ babel-preset-jest@27.5.1
      └─┬ babel-plugin-jest-hoist@27.5.1
        └── @types/babel__traverse@7.18.2 deduped

Expected Behavior

No error.

Current Behavior

When trying to build a typescript app you get the error message:

$ npm run build

node_modules/@types/babel__traverse/index.d.ts:68:50 - error TS1005: ']' expected.

68 export type ArrayKeys<T> = keyof { [P in keyof T as T[P] extends any[] ? P : never]: P };
                                                    ~~

node_modules/@types/babel__traverse/index.d.ts:68:53 - error TS1005: ';' expected.

68 export type ArrayKeys<T> = keyof { [P in keyof T as T[P] extends any[] ? P : never]: P };
                                                       ~

node_modules/@types/babel__traverse/index.d.ts:68:58 - error TS1005: ';' expected.

68 export type ArrayKeys<T> = keyof { [P in keyof T as T[P] extends any[] ? P : never]: P };
                                                            ~~~~~~~

node_modules/@types/babel__traverse/index.d.ts:68:70 - error TS1011: An element access expression should take an argument.

68 export type ArrayKeys<T> = keyof { [P in keyof T as T[P] extends any[] ? P : never]: P };
                                                                        

node_modules/@types/babel__traverse/index.d.ts:68:83 - error TS1005: ';' expected.

68 export type ArrayKeys<T> = keyof { [P in keyof T as T[P] extends any[] ? P : never]: P };
                                                                                     ~

node_modules/@types/babel__traverse/index.d.ts:68:84 - error TS1128: Declaration or statement expected.

68 export type ArrayKeys<T> = keyof { [P in keyof T as T[P] extends any[] ? P : never]: P };
                                                                                      ~

node_modules/@types/babel__traverse/index.d.ts:68:88 - error TS1128: Declaration or statement expected.

68 export type ArrayKeys<T> = keyof { [P in keyof T as T[P] extends any[] ? P : never]: P };
                                                                                          ~


Found 7 errors.

Reproduction Steps

Step 1 - create a new CDK app

cdk init --language=typescript app

Step 2 - Try to build

npm run build

Additional Information/Context

No response

CDK CLI Version

<=2.52.0
<=1.18.0

Framework Version

No response

Node.js Version

14+

OS

any

Language

Typescript

Language Version

<4.2

Other information

No response

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