client-side-base-visitor.ts

import { BaseVisitor, ParsedConfig, RawConfig } from './base-visitor';
import autoBind from 'auto-bind';
import { FragmentDefinitionNode, print, OperationDefinitionNode, visit, FragmentSpreadNode, GraphQLSchema } from 'graphql';
import { DepGraph } from 'dependency-graph';
import gqlTag from 'graphql-tag';
import { toPascalCase, Types } from '@graphql-codegen/plugin-helpers';
import { getConfigValue, buildScalars } from './utils';
import { LoadedFragment } from './types';
import { basename, extname } from 'path';
import { DEFAULT_SCALARS } from './scalars';

export enum DocumentMode {
  graphQLTag = 'graphQLTag',
  documentNode = 'documentNode',
  external = 'external',
  string = 'string',
}

const EXTENSIONS_TO_REMOVE = ['.ts', '.tsx', '.js', '.jsx'];

export interface RawClientSideBasePluginConfig extends RawConfig {
  noGraphQLTag?: boolean;
  gqlImport?: string;
  noExport?: boolean;
  dedupeOperationSuffix?: boolean;
  operationResultSuffix?: string;
  documentVariablePrefix?: string;
  documentVariableSuffix?: string;
  documentMode?: DocumentMode;
  importOperationTypesFrom?: string;
  importDocumentNodeExternallyFrom?: string;
}

export interface ClientSideBasePluginConfig extends ParsedConfig {
  /**
   * @name gqlImport
   * @type string
   * @default gql#graphql-tag
   * @description Customize from which module will `gql` be imported from.
   * This is useful if you want to use modules other than `graphql-tag`, e.g. `graphql.macro`.
   *
   * @example graphql.macro
   * ```yml
   * config:
   *   gqlImport: graphql.macro#gql
   * ```
   * @example Gatsby
   * ```yml
   * config:
   *   gqlImport: gatsby#graphql
   * ```
   */
  gqlImport: string;
  /**
   * @name operationResultSuffix
   * @type string
   * @default ""
   * @description Adds a suffix to generated operation result type names
   */
  operationResultSuffix: string;
  /**
   * @name dedupeOperationSuffix
   * @type boolean
   * @default false
   * @description Set this configuration to `true` if you wish to make sure to remove duplicate operation name suffix.
   */
  dedupeOperationSuffix: boolean;
  noExport: boolean;
  documentVariablePrefix: string;
  documentVariableSuffix: string;
  fragmentVariablePrefix: string;
  fragmentVariableSuffix: string;

  /**
   * @name documentMode
   * @type 'graphQLTag' | 'documentNode' | 'external'
   * @default 'graphQLTag'
   * @description Declares how DocumentNode are created:
   * - `graphQLTag`: `graphql-tag` or other modules (check `gqlImport`) will be used to generate document nodes. If this is used, document nodes are generated on client side i.e. the module used to generate this will be shipped to the client
   * - `documentNode`: document nodes will be generated as objects when we generate the templates.
   * - `external`: document nodes are imported from an external file. To be used with `importDocumentNodeExternallyFrom`
   */
  documentMode?: DocumentMode;

  /**
   * @name importDocumentNodeExternallyFrom
   * @type string | 'near-operation-file'
   * @default ''
   * @description This config should be used if `documentMode` is `external`. This has 2 usage:
   * - any string: This would be the path to import document nodes from. This can be used if we want to manually create the document nodes e.g. Use `graphql-tag` in a separate file and export the generated document
   * - 'near-operation-file': This is a special mode that is intended to be used with `near-operation-file` preset to import document nodes from those files. If these files are `.graphql` files, we make use of webpack loader.
   *
   * @example
   * ```yml
   * config:
   *   documentMode: external
   *   importDocumentNodeExternallyFrom: path/to/document-node-file
   * ```
   *
   * ```yml
   * config:
   *   documentMode: external
   *   importDocumentNodeExternallyFrom: near-operation-file
   * ```
   *
   */
  importDocumentNodeExternallyFrom?: string;

  // The following are internal, and used by presets
  importOperationTypesFrom?: string;
}

export class ClientSideBaseVisitor<TRawConfig extends RawClientSideBasePluginConfig = RawClientSideBasePluginConfig, TPluginConfig extends ClientSideBasePluginConfig = ClientSideBasePluginConfig> extends BaseVisitor<TRawConfig, TPluginConfig> {
  protected _collectedOperations: OperationDefinitionNode[] = [];
  protected _documents: Types.DocumentFile[] = [];
  protected _additionalImports: string[] = [];

  constructor(protected _schema: GraphQLSchema, protected _fragments: LoadedFragment[], rawConfig: TRawConfig, additionalConfig: Partial<TPluginConfig>, documents?: Types.DocumentFile[]) {
    super(rawConfig, {
      scalars: buildScalars(_schema, rawConfig.scalars, DEFAULT_SCALARS),
      dedupeOperationSuffix: getConfigValue(rawConfig.dedupeOperationSuffix, false),
      gqlImport: rawConfig.gqlImport || null,
      noExport: !!rawConfig.noExport,
      importOperationTypesFrom: getConfigValue(rawConfig.importOperationTypesFrom, null),
      operationResultSuffix: getConfigValue(rawConfig.operationResultSuffix, ''),
      documentVariablePrefix: getConfigValue(rawConfig.documentVariablePrefix, ''),
      documentVariableSuffix: getConfigValue(rawConfig.documentVariableSuffix, 'Document'),
      fragmentVariablePrefix: getConfigValue(rawConfig.documentVariablePrefix, ''),
      fragmentVariableSuffix: getConfigValue(rawConfig.documentVariableSuffix, 'FragmentDoc'),
      documentMode: ((rawConfig: RawClientSideBasePluginConfig) => {
        if (typeof rawConfig.noGraphQLTag === 'boolean') {
          return rawConfig.noGraphQLTag ? DocumentMode.documentNode : DocumentMode.graphQLTag;
        }
        return getConfigValue(rawConfig.documentMode, DocumentMode.graphQLTag);
      })(rawConfig),
      importDocumentNodeExternallyFrom: getConfigValue(rawConfig.importDocumentNodeExternallyFrom, ''),
      ...additionalConfig,
    } as any);

    this._documents = documents;

    autoBind(this);
  }

  protected _getFragmentName(fragment: FragmentDefinitionNode | string): string {
    return this.convertName(fragment, {
      suffix: this.config.fragmentVariableSuffix,
      prefix: this.config.fragmentVariablePrefix,
      useTypesPrefix: false,
    });
  }

  protected _extractFragments(document: FragmentDefinitionNode | OperationDefinitionNode): string[] {
    if (!document) {
      return [];
    }

    const names = [];

    visit(document, {
      enter: {
        FragmentSpread: (node: FragmentSpreadNode) => {
          names.push(node.name.value);
        },
      },
    });

    return names;
  }

  protected _transformFragments(document: FragmentDefinitionNode | OperationDefinitionNode): string[] {
    return this._extractFragments(document).map(document => this._getFragmentName(document));
  }

  protected _includeFragments(fragments: string[]): string {
    if (fragments && fragments.length > 0) {
      if (this.config.documentMode === DocumentMode.documentNode) {
        return `${fragments
          .filter((name, i, all) => all.indexOf(name) === i)
          .map(name => {
            const found = this._fragments.find(f => `${f.name}FragmentDoc` === name);

            if (found) {
              return print(found.node);
            }

            return null;
          })
          .filter(a => a)
          .join('\n')}`;
      } else {
        return `${fragments
          .filter((name, i, all) => all.indexOf(name) === i)
          .map(name => '${' + name + '}')
          .join('\n')}`;
      }
    }

    return '';
  }

  protected _prepareDocument(documentStr: string): string {
    return documentStr;
  }

  protected _gql(node: FragmentDefinitionNode | OperationDefinitionNode): string {
    const doc = this._prepareDocument(`
    ${
      print(node)
        .split('\\')
        .join('\\\\') /* Re-escape escaped values in GraphQL syntax */
    }
    ${this._includeFragments(this._transformFragments(node))}`);

    if (this.config.documentMode === DocumentMode.documentNode) {
      const gqlObj = gqlTag(doc);

      if (gqlObj && gqlObj['loc']) {
        delete gqlObj.loc;
      }

      return JSON.stringify(gqlObj);
    } else if (this.config.documentMode === DocumentMode.string) {
      return '`' + doc + '`';
    }

    return 'gql`' + doc + '`';
  }

  protected _generateFragment(fragmentDocument: FragmentDefinitionNode): string | void {
    const name = this._getFragmentName(fragmentDocument);

    return `export const ${name}${this.config.documentMode === DocumentMode.documentNode ? ': DocumentNode' : ''} = ${this._gql(fragmentDocument)};`;
  }

  private get fragmentsGraph(): DepGraph<LoadedFragment> {
    const graph = new DepGraph<LoadedFragment>({ circular: true });

    for (const fragment of this._fragments) {
      if (graph.hasNode(fragment.name)) {
        const cachedAsString = print(graph.getNodeData(fragment.name).node);
        const asString = print(fragment.node);

        if (cachedAsString !== asString) {
          throw new Error(`Duplicated fragment called '${fragment.name}'!`);
        }
      }

      graph.addNode(fragment.name, fragment);
    }

    this._fragments.forEach(fragment => {
      const depends = this._extractFragments(fragment.node);

      if (depends && depends.length > 0) {
        depends.forEach(name => {
          graph.addDependency(fragment.name, name);
        });
      }
    });

    return graph;
  }

  public get fragments(): string {
    if (this._fragments.length === 0 || this.config.documentMode === DocumentMode.external) {
      return '';
    }

    const graph = this.fragmentsGraph;
    const orderedDeps = graph.overallOrder();
    const localFragments = orderedDeps.filter(name => !graph.getNodeData(name).isExternal).map(name => this._generateFragment(graph.getNodeData(name).node));

    return localFragments.join('\n');
  }

  protected _parseImport(importStr: string) {
    const [moduleName, propName] = importStr.split('#');

    return {
      moduleName,
      propName,
    };
  }

  private clearExtension(path: string): string {
    const extension = extname(path);

    if (EXTENSIONS_TO_REMOVE.includes(extension)) {
      return path.replace(/\.[^/.]+$/, '');
    }

    return path;
  }

  public getImports(): string[] {
    let imports = [...this._additionalImports];

    switch (this.config.documentMode) {
      case DocumentMode.documentNode:
        imports.push(`import { DocumentNode } from 'graphql';`);
        break;
      case DocumentMode.graphQLTag:
        const gqlImport = this._parseImport(this.config.gqlImport || 'graphql-tag');
        imports.push(`import ${gqlImport.propName ? `{ ${gqlImport.propName === 'gql' ? 'gql' : `${gqlImport.propName} as gql`} }` : 'gql'} from '${gqlImport.moduleName}';`);
        break;
      case DocumentMode.external:
        if (this._collectedOperations.length > 0) {
          if (this.config.importDocumentNodeExternallyFrom === 'near-operation-file' && this._documents.length === 1) {
            imports.push(`import * as Operations from './${this.clearExtension(basename(this._documents[0].filePath))}';`);
          } else {
            imports.push(`import * as Operations from '${this.clearExtension(this.config.importDocumentNodeExternallyFrom)}';`);
          }
        }
        break;
      default:
        break;
    }

    if (this.config.documentMode === DocumentMode.graphQLTag) {
      (this._fragments || []).filter(f => f.isExternal && f.importFrom && (!f['level'] || (f['level'] !== undefined && f['level'] === 0))).forEach(externalFragment => {
        const identifierName = this._getFragmentName(externalFragment.name);

        imports.push(`import { ${identifierName} } from '${externalFragment.importFrom}';`);
      });
    }

    return imports;
  }

  protected buildOperation(node: OperationDefinitionNode, documentVariableName: string, operationType: string, operationResultType: string, operationVariablesTypes: string): string {
    return null;
  }

  public OperationDefinition(node: OperationDefinitionNode): string {
    if (!node.name || !node.name.value) {
      return null;
    }

    this._collectedOperations.push(node);

    const documentVariableName = this.convertName(node, {
      suffix: this.config.documentVariableSuffix,
      prefix: this.config.documentVariablePrefix,
      useTypesPrefix: false,
    });

    let documentString = '';
    if (this.config.documentMode !== DocumentMode.external) {
      documentString = `${this.config.noExport ? '' : 'export'} const ${documentVariableName}${this.config.documentMode === DocumentMode.documentNode ? ': DocumentNode' : ''} = ${this._gql(node)};`;
    }

    const operationType: string = toPascalCase(node.operation);
    const operationTypeSuffix: string = this.config.dedupeOperationSuffix && node.name.value.toLowerCase().endsWith(node.operation) ? '' : operationType;

    const operationResultType: string = this.convertName(node, {
      suffix: operationTypeSuffix + this._parsedConfig.operationResultSuffix,
    });
    const operationVariablesTypes: string = this.convertName(node, {
      suffix: operationTypeSuffix + 'Variables',
    });

    const additional = this.buildOperation(node, documentVariableName, operationType, operationResultType, operationVariablesTypes);

    return [documentString, additional].filter(a => a).join('\n');
  }
}