Error because npm promote ajv-keywords

[Val-istar-Guo]

Run npm list ajv ajv-keywords in my project:

├─┬ eslint@7.25.0
│ ├─┬ @eslint/eslintrc@0.4.0
│ │ └── ajv@6.12.6 
│ ├── ajv@6.12.6 
│ └─┬ table@6.6.0
│   └── ajv@8.2.0 
└─┬ mili@3.10.2
  ├── UNMET PEER DEPENDENCY ajv@8.2.0 
  ├── ajv-keywords@5.0.0 
  └─┬ npm@6.14.13
    └─┬ request@2.88.0
      └─┬ har-validator@5.1.5
        └── ajv@6.12.6 

My project don't depend on ajv, But the dependencies of my project depend on ajv and ajv-keywords. ajv-keyword was promote to ./node_modules/ajv-keyworkds because it isn't conflict, but ajv not.....

However the actual installation effect is：

├── ajv-keywords@5.0.0 
├─┬ eslint@7.25.0
│ ├─┬ @eslint/eslintrc@0.4.0
│ │ └── ajv@6.12.6 
│ ├── ajv@6.12.6 
│ └─┬ table@6.6.0
│   └── ajv@8.2.0 
└─┬ mili@3.10.2
  ├── UNMET PEER DEPENDENCY ajv@8.2.0 
  
  └─┬ npm@6.14.13
    └─┬ request@2.88.0
      └─┬ har-validator@5.1.5
        └── ajv@6.12.6 

And mili Throw Error:

Cannot find module 'ajv/dist/compile/codegen'
Require stack:
- ....../node_modules/ajv-keywords/dist/definitions/typeof.js
- ....../node_modules/ajv-keywords/dist/keywords/typeof.js

peerDependencies is not easy to use。。。

[medikoo]

I can confirm, that any installation with npm v6 of project that has:

• dependency that depends on ajv v8, ajv-keywords v5
• eslint (which depends on ajv v6)

Is getting broken, because npm installs ajv v6 and ajv-keywords v5 top level

[Val-istar-Guo]

I can confirm, that any installation with npm v6 of project that has:

• dependency that depends on ajv v8, ajv-keywords v5
• eslint (which depends on ajv v6)

Is getting broken, because npm installs ajv v6 and ajv-keywords v5 top level

I understand the reason for the error, but there is no way to solve this problem elegantly.
I have to run npm install ajv@8 in my project.
Even if my project doesn't require ajv8 directly.

[medikoo]

I understand the reason for the error, but there is no way to solve this problem elegantly.

This is a bug on the npm v6 side (see: npm/npm#19877) AFAIK it can be fixed simply by upgrading to npm v7 or later (default starting from Node.js v16). Otherwise, there's no reliable fix, assuming the current design of ajv-keywords

It could be worked around in ajv-keywords if similarly as ajv-format it'll drop peer dependency on AJV, so providing it with ajv instance would be good enough (cc @epoberezkin ).

In serverless we're considering hard-coding what we need from ajv-keywords (and it's just regex) into our package to workaround that until npm v6 is EOL

[Val-istar-Guo]

Thank you for your help. I guess my best solution is to wait for npm7 to be supported in my project.