add camelcase option to schema type generation

[MbBrainz]

This pr is regarding the implementation of the feature request in this issue: #213

This pr adds the following features:

• optional config parameter useCamelCasedProps
• camelcasing of schema type parameters.

The new config param useCamelCasedProps has the following effect on the schema:

    const schema: SchemaObject = {
      type: "object",
      properties: {
        ["foo_bar"]: {
          type: "string",
        },
      },
    };

// resulting type for `useCamelCasedProps == false` (as usual)
export type Test = {
          foo_bar?: string;
}

// resulting type for `useCamelCasedProps == true` with the new addition
export type Test = {
          fooBar?: string;
}

This pr is still in DRAFT because:

With the current state of this pr the fetchers will fail to get parse the received json correctly, as the received data will be in snake_case and the types to cast to would be in camelCase. A solution to make this work, would be a configurable adjustment to the fetcher template (./plugins/typescript/src/core/templates/fetcher.ts) that applies camelCase to incoming request data and that applies snake_case to outgoing data. (exact implementation is still to be figured out)

@fabien0102 Please let me know whether you would be interested in having this feature added, and if so i can try to spend the additional time needed to make this work. Any tips/comments/improvements are very welcome!

[MbBrainz]

@fb55 @fabien0102 @micha-f What do you think about this feature

[fabien0102]

Sorry for the late answer, I don’t think this feature is wanted here.

The "best" way to handle this, is to mutate the openapi schema before generation (you have some example in plugins/typescript/src/utils

The idea will be something like this:

// openapi-codegen.config.ts
import {
  generateSchemaTypes,
  generateReactQueryComponents,
} from "@openapi-codegen/typescript";
import { defineConfig } from "@openapi-codegen/cli";

export default defineConfig({
  github: {
    from: {
      source: "url",
      url: "https://api.apis.guru/v2/specs/github.com/1.1.4/openapi.yaml",
    },
    outputDir: "src/github",
    to: async (context) => {
      // HERE!
     camelizedAllOptions(context.openAPIDocument); // This function mutate the schema directly
      const filenamePrefix = "github";
      const { schemasFiles } = await generateSchemaTypes(context, {
        filenamePrefix,
      });
      await generateReactQueryComponents(context, {
        filenamePrefix,
        schemasFiles,
      });
    },
  },
});

And after, you need to deal with this in the generated ...Fetcher.ts to ensure everything is handled correctly.

I used this kind of setup in the past, it works well.