lib/handlers/base-assembly-documentation-handler.ts

// Copyright (c) 2021, Compiler Explorer Authors
// All rights reserved.
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import express from 'express';

import { AssemblyDocumentationResponse } from '../../types/features/assembly-documentation.interfaces';

export class BaseAssemblyDocumentationHandler {
    /**
     * Gather the assembly instruction information by the instruction name.
     *
     * Implementors should return null if the instruction is not supported.
     */
    // eslint-disable-next-line no-unused-vars
    getInstructionInformation(instruction: string): AssemblyDocumentationResponse | null {
        return null;
    }

    /**
     * Handle a request for assembly instruction documentation.
     *
     * Implementors should not have to override this.
     */
    handle(request: express.Request, response: express.Response) {
        // If the request had no opcode parameter, we should fail. This assumes
        // no assembly language has a __unknown_opcode instruction.
        const instruction = (request.params.opcode || '__UNKNOWN_OPCODE').toUpperCase();
        const information = this.getInstructionInformation(instruction);
        if (information === null) {
            return response.status(404).send({ error: `Unknown opcode '${instruction}'` });
        }
        // Accept either JSON or Plaintext Content-Type
        const requestedContentType = request.accepts(['text', 'json']);
        switch (requestedContentType) {
            case 'text': response.send(information.html); break;
            case 'json': response.send(information); break;
            default: response.status(406).send({ error: 'Not Acceptable' }); break;
        }
    }
}