[BUG][JS] Description - ApiClient.js generated 'User-Agent' header but should be optional

[dcmwong]

Description

When using our site in Chrome there is an error in the console:

Refused to set unsafe header "User-Agent"

We use the openapi-generator-cli tool that generates the ApiClient.js setting the header User-Agent even though we haven't specified it in the cli. There is no way, that we've seen, to tell the cli to not set the User-Agent header and therefore no way to remove the above error from Chrome, besides manually removing it after the build.

openapi-generator version

With version :

    "@openapitools/openapi-generator-cli": "^2.4.26",

The actual version in yarn is:
"resolved" "https://registry.npmjs.org/@openapitools/openapi-generator-cli/-/openapi-generator-cli-2.4.26.tgz"

Generation Details

We use: this command to generate our js client code

openapi-generator-cli generate -g javascript -i swagger.json -o api --additional-properties=usePromises=true

Steps to reproduce

Generate client js code by running the below command on an example swagger.json

openapi-generator-cli generate -g javascript -i swagger.json -o api --additional-properties=usePromises=true

Navigate to the generated code api/src/ApiClient.js you will see the User-Agent code is there:

        /**
         * The default HTTP headers to be included for all API calls.
         * @type {Array.<String>}
         * @default {}
         */
        this.defaultHeaders = {
            'User-Agent': 'OpenAPI-Generator/1.0.0/Javascript'
        };

        /**

Even though it wasn't specified.

Related issues/PRs

I believe
this commit was where the issue was introduced.

Suggest a fix

The mustache template should probably check to see if the User Agent variable was passed before generating it.

[davesargrad]

I have this problem as well. This is really an issue for us.
I've traced this to

callApi(path, httpMethod, pathParams,
        queryParams, headerParams, formParams, bodyParam, authNames, contentTypes, accepts,
        returnType, apiBasePath, callback)

The defaultHeaders found within the _this3: ApiClient scope:

It's been a few months since this bug report was first written. No one has picked this up. Does this imply that the openapi generator is no longer supported?

[davesargrad]

This is easily solved at the application tier. Simply by adding the following line after construction of an instance:

let defaultClient = ApiClient.instance
defaultClient.defaultHeaders = {}

I've tested this, and it eliminates the chrome error.

[wing328]

closed via #20367 to add an option to skip setting the default header in ApiClient.js