Function transform

packages/effect/src/unstable/http/HttpMiddleware.ts:488–530

(
    compression: HttpPlatform["Service"]["compression"],
    acceptEncoding: string | undefined,
    response: HttpServerResponse
  )

    zstd: { level: levels.zstd }
  }
  const transform = (
    compression: HttpPlatform["Service"]["compression"],
    acceptEncoding: string | undefined,
    response: HttpServerResponse
  ): Effect.Effect<HttpServerResponse> => {
    if (
      response.status < 200 ||
      response.status === 204 ||
      response.status === 206 ||
      response.status === 304
    ) {
      return Effect.succeed(response)
    }
    const currentEncoding = response.headers["content-encoding"]
    if (currentEncoding !== undefined) {
      return Effect.succeed(
        currentEncoding.trim().toLowerCase() === "identity"
          ? Response.removeHeader(response, "content-encoding")
          : response
      )
    }
    const body = response.body
    if (body._tag === "Empty" || body._tag === "FormData") {
      return Effect.succeed(response)
    }
    const cacheControl = response.headers["cache-control"]
    if (cacheControl !== undefined && noTransformRegex.test(cacheControl)) {
      return Effect.succeed(response)
    }
    const contentType = response.headers["content-type"] ?? body.contentType
    if (contentType === undefined || !compressible(contentType)) {
      return Effect.succeed(response)
    }
    const algorithm = compressionInternal.negotiate(acceptEncoding, preferred, compression.algorithms)
    if (algorithm === undefined) {
      return Effect.succeed(withVary(response))
    }
    const contentLength = body.contentLength ?? contentLengthHeader(response.headers)
    if (contentLength !== undefined && contentLength < minSize) {
      return Effect.succeed(withVary(response))
    }
    return compression.compressResponse(response, algorithm, levelOptions[algorithm])
  }
  return <E, R>(
    httpApp: Effect.Effect<HttpServerResponse, E, R>
  ): Effect.Effect<HttpServerResponse, E, R | HttpServerRequest | HttpPlatform> =>