function emitPagerDefinition()

in packages/codegen.go/src/operations.ts [340:412]
68 lines of code
11 McCabe index (conditional complexity)

function emitPagerDefinition(client: go.Client, method: go.PageableMethod, imports: ImportManager, injectSpans: boolean, generateFakes: boolean): string {
  imports.add('context');
  let text = `runtime.NewPager(runtime.PagingHandler[${method.responseEnvelope.name}]{\n`;
  text += `\t\tMore: func(page ${method.responseEnvelope.name}) bool {\n`;
  // there is no advancer for single-page pagers
  if (method.nextLinkName) {
    text += `\t\t\treturn page.${method.nextLinkName} != nil && len(*page.${method.nextLinkName}) > 0\n`;
    text += '\t\t},\n';
  } else {
    text += '\t\t\treturn false\n';
    text += '\t\t},\n';
  }
  text += `\t\tFetcher: func(ctx context.Context, page *${method.responseEnvelope.name}) (${method.responseEnvelope.name}, error) {\n`;
  const reqParams = helpers.getCreateRequestParameters(method);
  if (generateFakes) {
    text += `\t\tctx = context.WithValue(ctx, runtime.CtxAPINameKey{}, "${client.name}.${fixUpMethodName(method)}")\n`;
  }
  if (method.nextLinkName) {
    let nextLinkVar: string;
    if (!go.isLROMethod(method)) {
      text += '\t\t\tnextLink := ""\n';
      nextLinkVar = 'nextLink';
      text += '\t\t\tif page != nil {\n';
      text += `\t\t\t\tnextLink = *page.${method.nextLinkName}\n\t\t\t}\n`;
    } else {
      nextLinkVar = `*page.${method.nextLinkName}`;
    }
    text += `\t\t\tresp, err := runtime.FetcherForNextLink(ctx, client.internal.Pipeline(), ${nextLinkVar}, func(ctx context.Context) (*policy.Request, error) {\n`;
    text += `\t\t\t\treturn client.${method.naming.requestMethod}(${reqParams})\n\t\t\t}, `;
    // nextPageMethod might be absent in some cases, see https://github.com/Azure/autorest/issues/4393
    if (method.nextPageMethod) {
      const nextOpParams = helpers.getCreateRequestParametersSig(method.nextPageMethod).split(',');
      // keep the parameter names from the name/type tuples and find nextLink param
      for (let i = 0; i < nextOpParams.length; ++i) {
        const paramName = nextOpParams[i].trim().split(' ')[0];
        const paramType = nextOpParams[i].trim().split(' ')[1];
        if (paramName.startsWith('next') && paramType === 'string') {
          nextOpParams[i] = 'encodedNextLink';
        } else {
          nextOpParams[i] = paramName;
        }
      }
      // add a definition for the nextReq func that uses the nextLinkOperation
      text += '&runtime.FetcherForNextLinkOptions{\n\t\t\t\tNextReq: func(ctx context.Context, encodedNextLink string) (*policy.Request, error) {\n';
      text += `\t\t\t\t\treturn client.${method.nextPageMethod.name}(${nextOpParams.join(', ')})\n\t\t\t\t},\n\t\t\t})\n`;
    } else {
      text += 'nil)\n';
    }
    text += `\t\t\tif err != nil {\n\t\t\t\treturn ${method.responseEnvelope.name}{}, err\n\t\t\t}\n`;
    text += `\t\t\treturn client.${method.naming.responseMethod}(resp)\n`;
    text += '\t\t\t},\n';
  } else {
    // this is the singular page case, no fetcher helper required
    text += `\t\t\treq, err := client.${method.naming.requestMethod}(${reqParams})\n`;
    text += '\t\t\tif err != nil {\n';
    text += `\t\t\t\treturn ${method.responseEnvelope.name}{}, err\n`;
    text += '\t\t\t}\n';
    text += '\t\t\tresp, err := client.internal.Pipeline().Do(req)\n';
    text += '\t\t\tif err != nil {\n';
    text += `\t\t\t\treturn ${method.responseEnvelope.name}{}, err\n`;
    text += '\t\t\t}\n';
    text += '\t\t\tif !runtime.HasStatusCode(resp, http.StatusOK) {\n';
    text += `\t\t\t\treturn ${method.responseEnvelope.name}{}, runtime.NewResponseError(resp)\n`;
    text += '\t\t\t}\n';
    text += `\t\t\treturn client.${method.naming.responseMethod}(resp)\n`;
    text += '\t\t},\n';
  }
  if (injectSpans) {
    text += '\t\tTracer: client.internal.Tracer(),\n';
  }
  text += '\t})\n';
  return text;
}