wip: implement parser extensions for transforming the fragment argument transform syntax into operations without fragment arguments, which are executable by all graphql.js versions

n1ru4l · n1ru4l · commit 2923c6026599 · 2021-06-04T10:42:53.000+02:00
See graphql/graphql-js#3152 for reference
diff --git a/packages/plugins/fragment-arguments/package.json b/packages/plugins/fragment-arguments/package.json
@@ -0,0 +1,41 @@
+{
+  "name": "@envelop/fragment-arguments",
+  "version": "0.0.1",
+  "author": "Dotan Simha <dotansimha@gmail.com>",
+  "license": "MIT",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/dotansimha/envelop.git",
+    "directory": "packages/plugins/fragment-arguments"
+  },
+  "sideEffects": false,
+  "main": "dist/index.cjs.js",
+  "module": "dist/index.esm.js",
+  "typings": "dist/index.d.ts",
+  "typescript": {
+    "definition": "dist/index.d.ts"
+  },
+  "scripts": {
+    "test": "jest",
+    "prepack": "bob prepack"
+  },
+  "devDependencies": {
+    "@types/common-tags": "1.8.0",
+    "@graphql-tools/schema": "7.1.5",
+    "bob-the-bundler": "1.2.1",
+    "graphql": "15.5.0",
+    "typescript": "4.3.2",
+    "oneline": "1.0.3",
+    "common-tags": "1.8.0"
+  },
+  "peerDependencies": {
+    "graphql": "^14.0.0 || ^15.0.0"
+  },
+  "buildOptions": {
+    "input": "./src/index.ts"
+  },
+  "publishConfig": {
+    "directory": "dist",
+    "access": "public"
+  }
+}
diff --git a/packages/plugins/fragment-arguments/src/index.ts b/packages/plugins/fragment-arguments/src/index.ts
@@ -0,0 +1,163 @@
+import { Plugin } from '@envelop/types';
+import { Parser, ParseOptions } from 'graphql/language/parser';
+import { Lexer } from 'graphql/language/lexer';
+
+import {
+  TokenKind,
+  Kind,
+  Source,
+  DocumentNode,
+  visit,
+  FragmentDefinitionNode,
+  InlineFragmentNode,
+  ArgumentNode,
+  TokenKindEnum,
+  Token,
+} from 'graphql';
+
+declare module 'graphql/language/parser' {
+  export class Parser {
+    constructor(source: string | Source, options?: ParseOptions);
+    _lexer: Lexer;
+    expectOptionalKeyword(word: string): boolean;
+    expectToken(token: TokenKindEnum): void;
+    peek(token: TokenKindEnum): boolean;
+    parseFragmentName(): string;
+    parseArguments(flag: boolean): any;
+    parseDirectives(flag: boolean): any;
+    loc(start: Token): any;
+    parseNamedType(): any;
+    parseSelectionSet(): any;
+    expectKeyword(keyword: string): void;
+    parseVariableDefinitions(): void;
+    parseDocument(): DocumentNode;
+  }
+}
+
+class FragmentArgumentCompatible extends Parser {
+  parseFragment() {
+    const start = this._lexer.token;
+    this.expectToken(TokenKind.SPREAD);
+    const hasTypeCondition = this.expectOptionalKeyword('on');
+    if (!hasTypeCondition && this.peek(TokenKind.NAME)) {
+      const name = this.parseFragmentName();
+      if (this.peek(TokenKind.PAREN_L)) {
+        return {
+          kind: Kind.FRAGMENT_SPREAD,
+          name,
+          arguments: this.parseArguments(false),
+          directives: this.parseDirectives(false),
+          loc: this.loc(start),
+        };
+      }
+      return {
+        kind: Kind.FRAGMENT_SPREAD,
+        name: this.parseFragmentName(),
+        directives: this.parseDirectives(false),
+        loc: this.loc(start),
+      };
+    }
+    return {
+      kind: Kind.INLINE_FRAGMENT,
+      typeCondition: hasTypeCondition ? this.parseNamedType() : undefined,
+      directives: this.parseDirectives(false),
+      selectionSet: this.parseSelectionSet(),
+      loc: this.loc(start),
+    };
+  }
+
+  parseFragmentDefinition() {
+    const start = this._lexer.token;
+    this.expectKeyword('fragment');
+    const name = this.parseFragmentName();
+    if (this.peek(TokenKind.PAREN_L)) {
+      return {
+        kind: Kind.FRAGMENT_DEFINITION,
+        name,
+        variableDefinitions: this.parseVariableDefinitions(),
+        typeCondition: (this.expectKeyword('on'), this.parseNamedType()),
+        directives: this.parseDirectives(false),
+        selectionSet: this.parseSelectionSet(),
+        loc: this.loc(start),
+      };
+    }
+
+    return {
+      kind: Kind.FRAGMENT_DEFINITION,
+      name,
+      typeCondition: (this.expectKeyword('on'), this.parseNamedType()),
+      directives: this.parseDirectives(false),
+      selectionSet: this.parseSelectionSet(),
+      loc: this.loc(start),
+    };
+  }
+}
+
+function pimpedParse(source: string | Source, options?: ParseOptions): DocumentNode {
+  const parser = new FragmentArgumentCompatible(source, options);
+  return parser.parseDocument();
+}
+
+export const useFragmentArguments = (): Plugin => {
+  return {
+    onParse({ setParseFn }) {
+      setParseFn(pimpedParse);
+
+      return ({ result, replaceParseResult }) => {
+        if (result && 'kind' in result) {
+          replaceParseResult(applySelectionSetFragmentArguments(result));
+        }
+      };
+    },
+  };
+};
+
+function applySelectionSetFragmentArguments(document: DocumentNode): DocumentNode | Error {
+  const fragmentList = new Map<string, FragmentDefinitionNode>();
+  for (const def of document.definitions) {
+    if (def.kind !== 'FragmentDefinition') {
+      continue;
+    }
+    fragmentList.set(def.name.value, def);
+  }
+
+  return visit(document, {
+    FragmentSpread(fragmentNode) {
+      // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+      // @ts-ignore
+      if (fragmentNode.arguments != null && fragmentNode.arguments.length) {
+        const fragmentDef = fragmentList.get(fragmentNode.name.value);
+        if (!fragmentDef) {
+          return;
+        }
+
+        const fragmentArguments = new Map<string, ArgumentNode>();
+        // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+        // @ts-ignore
+        for (const arg of fragmentNode.arguments) {
+          fragmentArguments.set(arg.name.value, arg);
+        }
+
+        const selectionSet = visit(fragmentDef.selectionSet, {
+          Variable(variableNode) {
+            const fragArg = fragmentArguments.get(variableNode.name.value);
+            if (fragArg) {
+              return fragArg.value;
+            }
+
+            return variableNode;
+          },
+        });
+
+        const inlineFragment: InlineFragmentNode = {
+          kind: 'InlineFragment',
+          typeCondition: fragmentDef.typeCondition,
+          selectionSet,
+        };
+
+        return inlineFragment;
+      }
+      return fragmentNode;
+    },
+  });
+}
diff --git a/packages/plugins/fragment-arguments/test/use-fragment-arguments.spec.ts b/packages/plugins/fragment-arguments/test/use-fragment-arguments.spec.ts
@@ -0,0 +1,87 @@
+import { buildSchema, print } from 'graphql';
+import { oneLine, stripIndent } from 'common-tags';
+import { diff } from 'jest-diff';
+import { envelop, useSchema } from '@envelop/core';
+import { useFragmentArguments } from '../src';
+
+function compareStrings(a: string, b: string): boolean {
+  return a.includes(b);
+}
+
+expect.extend({
+  toBeSimilarStringTo(received: string, expected: string) {
+    const strippedReceived = oneLine`${received}`.replace(/\s\s+/g, ' ');
+    const strippedExpected = oneLine`${expected}`.replace(/\s\s+/g, ' ');
+
+    if (compareStrings(strippedReceived, strippedExpected)) {
+      return {
+        message: () =>
+          `expected 
+   ${received}
+   not to be a string containing (ignoring indents)
+   ${expected}`,
+        pass: true,
+      };
+    } else {
+      const diffString = diff(stripIndent`${expected}`, stripIndent`${received}`, {
+        expand: this.expand,
+      });
+      const hasExpect = diffString && diffString.includes('- Expect');
+
+      const message = hasExpect
+        ? `Difference:\n\n${diffString}`
+        : `expected 
+      ${received}
+      to be a string containing (ignoring indents)
+      ${expected}`;
+
+      return {
+        message: () => message,
+        pass: false,
+      };
+    }
+  },
+});
+
+declare global {
+  // eslint-disable-next-line no-redeclare
+  namespace jest {
+    interface Matchers<R, T> {
+      /**
+       * Normalizes whitespace and performs string comparisons
+       */
+      toBeSimilarStringTo(expected: string): R;
+    }
+  }
+}
+
+describe('useFragmentArguments', () => {
+  const schema = buildSchema(/* GraphQL */ `
+    type Query {
+      a: TestType
+    }
+
+    type TestType {
+      a(b: String): Boolean
+    }
+  `);
+  test('can inline fragment with argument', () => {
+    const { parse } = envelop({ plugins: [useFragmentArguments(), useSchema(schema)] })();
+    const result = parse(/* GraphQL */ `
+      fragment TestFragment($c: String) on Query {
+        a(b: $c)
+      }
+
+      query TestQuery($a: String) {
+          ...TestFragment(c: $a)
+      }
+    `);
+    expect(print(result)).toBeSimilarStringTo(/* GraphQL */ `
+      query TestQuery($a: String) {
+        ... on Query {
+          a(b: $a)
+        }
+      }
+    `);
+  });
+});
diff --git a/yarn.lock b/yarn.lock
@@ -1300,6 +1300,11 @@
     "@types/connect" "*"
     "@types/node" "*"
 
+"@types/common-tags@1.8.0":
+  version "1.8.0"
+  resolved "https://registry.yarnpkg.com/@types/common-tags/-/common-tags-1.8.0.tgz#79d55e748d730b997be5b7fce4b74488d8b26a6b"
+  integrity sha512-htRqZr5qn8EzMelhX/Xmx142z218lLyGaeZ3YR8jlze4TATRU9huKKvuBmAJEW4LCC4pnY1N6JAm6p85fMHjhg==
+
 "@types/connect@*":
   version "3.4.34"
   resolved "https://registry.npmjs.org/@types/connect/-/connect-3.4.34.tgz#170a40223a6d666006d93ca128af2beb1d9b1901"
@@ -2565,6 +2570,11 @@ commander@^7.2.0:
   resolved "https://registry.yarnpkg.com/commander/-/commander-7.2.0.tgz#a36cb57d0b501ce108e4d20559a150a391d97ab7"
   integrity sha512-QrWXB+ZQSVPmIWIhtEO9H+gwHaMGYiF5ChvoJ+K9ZGHG/sVsa6yiesAD1GC/x46sET00Xlwo1u49RVVVzvcSkw==
 
+common-tags@1.8.0:
+  version "1.8.0"
+  resolved "https://registry.yarnpkg.com/common-tags/-/common-tags-1.8.0.tgz#8e3153e542d4a39e9b10554434afaaf98956a937"
+  integrity sha512-6P6g0uetGpW/sdyUy/iQQCbFF0kWVMSIVSyYz7Zgjcgh8mgw8PQzDNZeyZ5DQ2gM7LBoZPHmnjz8rUthkBG5tw==
+
 commondir@^1.0.1:
   version "1.0.1"
   resolved "https://registry.npmjs.org/commondir/-/commondir-1.0.1.tgz#ddd800da0c66127393cca5950ea968a3aaf1253b"
@@ -5748,6 +5758,11 @@ once@^1.3.0, once@^1.3.1, once@^1.4.0:
   dependencies:
     wrappy "1"
 
+oneline@1.0.3:
+  version "1.0.3"
+  resolved "https://registry.yarnpkg.com/oneline/-/oneline-1.0.3.tgz#2f2631bd3a5716a4eeb439291697af2fc7fa39a5"
+  integrity sha512-KWLrLloG/ShWvvWuvmOL2jw17++ufGdbkKC2buI2Aa6AaM4AkjCtpeJZg60EK34NQVo2qu1mlPrC2uhvQgCrhQ==
+
 onetime@^5.1.0, onetime@^5.1.2:
   version "5.1.2"
   resolved "https://registry.npmjs.org/onetime/-/onetime-5.1.2.tgz#d0e96ebb56b07476df1dd9c4806e5237985ca45e"
