Introduction
In my current job, we recently encountered a scenario where we needed to upgrade google-cloud pubsub to version 3 for one microservice, while still maintaining version 2 for the other microservices. Thankfully, we were able to leverage the npm aliasing feature to solve this issue.
Package alias allows installation of packages with custom names.
Installation
To install the package lodash with a custom name my_lodash, we can add the below line in package.json and run npm install to install the package:
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"dependencies": {
"my_lodash": "npm:lodash"
}
Or, we can install it using the below command: npm install my_lodash@npm:lodash --save
We can specify a specific package version during installation:
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"dependencies": {
"lodash_v3": "npm:lodash@^3.10.1",
"lodash_v4": "npm:lodash@^4.17.21",
}
Or, we can install it using the below command: npm install lodash_v3@npm:lodash@3.10.1 --save
While installation it will use the specific name provided when it adds it to node_modules.
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├── node_modules
│ ├── lodash_v3
│ └── lodash_v4
├── package-lock.json
├── package.json
Usage
We can use the custom name while importing the module.
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import { pluck } from 'lodash_v3' // pluck is removed in v4
import { reverse } from 'lodash_v4' // reverse is not introduced till v3
Conclusion
Similar to the above example, We resolved the issue of conflicting package versions by installing two separate versions of google-cloud pubsub under different names.