Testing infrastructure improvements

.vscode/tasks.json

@@ -0,0 +1,25 @@
+{
+  "version": "2.0.0",
+  "tasks": [
+    {
+      "label": "TypeScript watch",
+      "type": "typescript",
+      "tsconfig": "tsconfig.json",
+      "option": "watch",
+      "problemMatcher": ["$tsc-watch"],
+      "group": {
+        "kind": "build",
+        "isDefault": true
+      },
+      "presentation": {
+        "reveal": "never",
+        "revealProblems": "onProblem",
+        "panel": "shared",
+        "clear": true
+      },
+      "runOptions": {
+        "runOn": "folderOpen"
+      }
+    }
+  ]
+}

federation-integration-testsuite-js/src/index.ts

@@ -1 +1,5 @@
+export * from './matchers';
+export * from './snapshotSerializers';
 export * from './fixtures';
+
+export { prettyFormatQueryPlan } from './prettyFormatQueryPlan';

federation-integration-testsuite-js/src/matchers/index.ts

@@ -0,0 +1,4 @@
+import './toCallService';
+import './toHaveBeenCalledBefore';
+import './toHaveFetched';
+import './toMatchAST';

gateway-js/src/__tests__/matchers/toCallService.ts → federation-integration-testsuite-js/src/matchers/toCallService.ts

@@ -1,12 +1,11 @@
-import { QueryPlan } from '@apollo/gateway';
-import { PlanNode } from '../../QueryPlan';
-import astSerializer from '../../snapshotSerializers/astSerializer';
-import queryPlanSerializer from '../../snapshotSerializers/queryPlanSerializer';
+import { QueryPlan, PlanNode } from '@apollo/gateway';
+import astSerializer from '../snapshotSerializers/astSerializer';
+import queryPlanSerializer from '../snapshotSerializers/queryPlanSerializer';
 const prettyFormat = require('pretty-format');
 
 declare global {
   namespace jest {
-    interface Matchers<R, T> {
+    interface Matchers<R> {
       toCallService(service: string): R;
     }
   }

gateway-js/src/__tests__/matchers/toHaveBeenCalledBefore.ts → federation-integration-testsuite-js/src/matchers/toHaveBeenCalledBefore.ts

@@ -3,8 +3,8 @@
 export {};
 declare global {
   namespace jest {
-    interface Matchers<R, T> {
-      toHaveBeenCalledBefore(spy: SpyInstance): R;
+    interface Matchers<R> {
+      toHaveBeenCalledBefore(secondSpy: jest.SpyInstance): R;
     }
   }
 }

gateway-js/src/__tests__/matchers/toHaveFetched.ts → federation-integration-testsuite-js/src/matchers/toHaveFetched.ts

@@ -5,8 +5,9 @@ import { RequestInit, Headers } from 'apollo-server-env';
 export {};
 declare global {
   namespace jest {
-    interface Matchers<R, T> {
-      toHaveFetched(spy: SpyInstance): R;
+    interface Matchers<R> {
+      toHaveFetched(requestUrl: string, requestOpts?: RequestInit): R;
+      toHaveFetchedNth(nthCall: number, requestUrl: string, requestOpts?: RequestInit): R;
     }
   }
 }
@@ -15,8 +16,8 @@ function prepareHttpOptions(requestUrl: string, requestOpts: RequestInit): Reque
   const headers = new Headers();
   headers.set('Content-Type', 'application/json');
   if (requestOpts.headers) {
-    for (let name in requestOpts.headers) {
-      headers.set(name, requestOpts.headers[name]);
+    for (const [name, value] of new Headers(requestOpts.headers)) {
+      headers.set(name, value);
     }
   }
 
@@ -37,7 +38,7 @@ function toHaveFetched(
   this: jest.MatcherUtils,
   fetch: jest.SpyInstance,
   requestUrl: string,
-  requestOpts: RequestInit
+  requestOpts: RequestInit = {}
 ): { message(): string; pass: boolean } {
   const httpOptions = prepareHttpOptions(requestUrl, requestOpts);
   let pass = false;
@@ -60,7 +61,7 @@ function toHaveFetchedNth(
   fetch: jest.SpyInstance,
   nthCall: number,
   requestUrl: string,
-  requestOpts: RequestInit
+  requestOpts: RequestInit = {}
 ): { message(): string; pass: boolean } {
   const httpOptions = prepareHttpOptions(requestUrl, requestOpts);
   let pass = false;

federation-integration-testsuite-js/src/matchers/toMatchAST.ts

@@ -0,0 +1,43 @@
+import { ASTNode } from 'graphql';
+import { MatcherHintOptions } from 'jest-matcher-utils';
+import { diffFormatted, indentLines, printExpectedFormatted } from './utils';
+
+declare global {
+  namespace jest {
+    interface Matchers<R> {
+      toMatchAST(expected: ASTNode): R;
+    }
+  }
+}
+
+expect.extend({
+  toMatchAST(received: ASTNode, expected: ASTNode) {
+    const matcherName = 'toMatchAST';
+    const options: MatcherHintOptions = {
+      isNot: this.isNot,
+      promise: this.promise,
+    };
+
+    const pass = this.equals(received, expected);
+
+    const message = pass
+      ? () =>
+          this.utils.matcherHint(matcherName, undefined, undefined, options) +
+          '\n\n' +
+          `Expected AST to not equal:\n` +
+          indentLines(printExpectedFormatted(expected))
+      : () =>
+          this.utils.matcherHint(matcherName, undefined, undefined, options) +
+          '\n\n' +
+          diffFormatted(expected, received, {
+            aAnnotation: 'Expected',
+            bAnnotation: 'Received',
+            expand: this.expand ?? true,
+            includeChangeCounts: true,
+          });
+    return {
+      message,
+      pass,
+    };
+  },
+});

federation-integration-testsuite-js/src/matchers/toMatchQueryPlan.ts

@@ -0,0 +1,43 @@
+import { QueryPlan } from '@apollo/gateway';
+import { MatcherHintOptions } from 'jest-matcher-utils';
+import { diffFormatted, indentLines, printExpectedFormatted } from './utils';
+
+declare global {
+  namespace jest {
+    interface Matchers<R> {
+      toMatchQueryPlan(expected: QueryPlan): R;
+    }
+  }
+}
+
+expect.extend({
+  toMatchQueryPlan(received: QueryPlan, expected: QueryPlan) {
+    const matcherName = 'toMatchQueryPlan';
+    const options: MatcherHintOptions = {
+      isNot: this.isNot,
+      promise: this.promise,
+    };
+
+    const pass = this.equals(received, expected);
+
+    const message = pass
+      ? () =>
+          this.utils.matcherHint(matcherName, undefined, undefined, options) +
+          '\n\n' +
+          `Expected query plan to not equal:\n` +
+          indentLines(printExpectedFormatted(expected))
+      : () =>
+          this.utils.matcherHint(matcherName, undefined, undefined, options) +
+          '\n\n' +
+          diffFormatted(expected, received, {
+            aAnnotation: 'Expected',
+            bAnnotation: 'Received',
+            expand: this.expand ?? true,
+            includeChangeCounts: true,
+          });
+    return {
+      message,
+      pass,
+    };
+  },
+});

federation-integration-testsuite-js/src/matchers/utils.ts

@@ -0,0 +1,53 @@
+import diff, { DiffOptions } from 'jest-diff';
+import { EXPECTED_COLOR, RECEIVED_COLOR } from 'jest-matcher-utils';
+import prettyFormat from 'pretty-format';
+import {
+  queryPlanSerializer,
+  astSerializer,
+  typeSerializer,
+} from '../snapshotSerializers';
+
+const defaultFormatOptions: prettyFormat.OptionsReceived = {
+  plugins: [queryPlanSerializer, astSerializer, typeSerializer],
+};
+
+export function diffFormatted(
+  expected: unknown,
+  received: unknown,
+  diffOptions?: DiffOptions,
+  formatOptions: prettyFormat.OptionsReceived = defaultFormatOptions,
+) {
+  const expectedString = prettyFormat(expected, formatOptions);
+  const receivedString = prettyFormat(received, formatOptions);
+
+  return diff(expectedString, receivedString, diffOptions);
+}
+
+export function indentLines(
+  text: string,
+  depth: number = 1,
+  indent: string = ' ',
+) {
+  const indentation = indent.repeat(depth);
+  return text
+    .split('\n')
+    .map((line) => indentation + line)
+    .join('\n');
+}
+
+// The corresponding functions in `jest-matcher-utils` call their own `stringify` function,
+// and that doesn't allow passing in custom pretty-format plugins.
+
+export function printReceivedFormatted(
+  value: unknown,
+  formatOptions: prettyFormat.OptionsReceived = defaultFormatOptions,
+): string {
+  return RECEIVED_COLOR(prettyFormat(value, formatOptions));
+}
+
+export function printExpectedFormatted(
+  value: unknown,
+  formatOptions: prettyFormat.OptionsReceived = defaultFormatOptions,
+): string {
+  return EXPECTED_COLOR(prettyFormat(value, formatOptions));
+}

federation-integration-testsuite-js/src/prettyFormatQueryPlan.ts

@@ -0,0 +1,9 @@
+import { QueryPlan } from '@apollo/gateway';
+import prettyFormat from 'pretty-format';
+import { astSerializer, queryPlanSerializer } from './snapshotSerializers';
+
+export function prettyFormatQueryPlan(queryPlan: QueryPlan) {
+  return prettyFormat(queryPlan, {
+    plugins: [queryPlanSerializer, astSerializer],
+  });
+}

gateway-js/src/snapshotSerializers/astSerializer.ts → federation-integration-testsuite-js/src/snapshotSerializers/astSerializer.ts

@@ -1,27 +1,57 @@
-import { ASTNode, print, Kind, visit } from 'graphql';
-import { Plugin, Config, Refs } from 'pretty-format';
-import { QueryPlanSelectionNode, QueryPlanInlineFragmentNode } from '../QueryPlan';
-import { SelectionNode as GraphQLJSSelectionNode } from 'graphql';
+import { QueryPlanInlineFragmentNode, QueryPlanSelectionNode } from '@apollo/gateway';
+import { ASTNode, Kind, print, SelectionNode as GraphQLJSSelectionNode, visit } from 'graphql';
+import { Config, NewPlugin, Refs } from 'pretty-format';
 
 export default {
   test(value: any) {
+    // Note that this isn't a reliable test because other objects may also have a `kind` property
+    // (like query plans!).
+    // `graphql-js` does have an unexported `isNode` function, but that currently performs the same check
+    // and doesn't check whether `kind` represents a valid AST node either:
+    // https://github.com/graphql/graphql-js/blob/998bea680d6e11e1c055a400a887a9539de08f75/src/language/ast.js#L135-L137
+    // Perhaps we should attempt to contribute an improved `isNode` function.
     return value && typeof value.kind === 'string';
   },
 
   serialize(
     value: ASTNode,
-    _config: Config,
+    config: Config,
     indentation: string,
     _depth: number,
     _refs: Refs,
     _printer: any,
   ): string {
-    return print(remapInlineFragmentNodes(value))
-      .trim()
-      .replace(/\n\n/g, '\n')
-      .replace(/\n/g, '\n' + indentation);
+    const lines = print(remapInlineFragmentNodes(value)).trim().split('\n');
+
+    // Avoid adding newlines for single line results.
+    if (lines.length === 0) {
+      return '';
+    } else if (lines.length === 1) {
+      return lines[0];
+    }
+
+    return lines.map(line => {
+      // We re-indent the lines printed from `graphql-js` to respect the passed in `indentation`
+      // and`config.indent` values.
+      // This is important because Jest has started to ignore indentation when diffing snapshots,
+      // and it does this by invoking snapshot serializers with these values set to 0.
+      // Without re-indenting, every line printed from `graphql-js` would be shown as changed.
+      // See https://github.com/facebook/jest/pull/9203
+      const indentationLength = getIndentationLength(line);
+      const dedentedLine = line.slice(indentationLength);
+      // `graphql-js` always indents with 2 spaces
+      const indentationDepth = indentationLength / 2;
+
+      return indentation + config.indent.repeat(indentationDepth) + dedentedLine;
+    }).join(config.spacingOuter);
   },
-} as Plugin;
+} as NewPlugin;
+
+// From https://github.com/facebook/jest/blob/32aaff83f02c347ccd591727544002490fb4ee9a/packages/jest-snapshot/src/dedentLines.ts#L8
+function getIndentationLength(line: string): number {
+  const result = /^( {2})+/.exec(line);
+  return result === null ? 0 : result[0].length;
+};
 
 /**
  * This function converts potential InlineFragmentNodes that WE created
@@ -79,7 +109,7 @@ export function remapInlineFragmentNodes(node: ASTNode): ASTNode {
 
 function remapSelections(
   selections: QueryPlanSelectionNode[],
-): ReadonlyArray<GraphQLJSSelectionNode> {
+): readonly GraphQLJSSelectionNode[] {
   return selections.map((selection) => {
     switch (selection.kind) {
       case Kind.FIELD:

federation-js/src/snapshotSerializers/index.ts → federation-integration-testsuite-js/src/snapshotSerializers/index.ts

@@ -2,14 +2,4 @@ export { default as astSerializer } from './astSerializer';
 export { default as selectionSetSerializer } from './selectionSetSerializer';
 export { default as typeSerializer } from './typeSerializer';
 export { default as graphqlErrorSerializer } from './graphqlErrorSerializer';
-
-declare global {
-  namespace jest {
-    interface Expect {
-      /**
-       * Adds a module to format application-specific data structures for serialization.
-       */
-      addSnapshotSerializer(serializer: import('pretty-format').Plugin): void;
-    }
-  }
-}
+export { default as queryPlanSerializer } from './queryPlanSerializer';

gateway-js/src/snapshotSerializers/queryPlanSerializer.ts → federation-integration-testsuite-js/src/snapshotSerializers/queryPlanSerializer.ts

@@ -1,5 +1,5 @@
 import { Config, Plugin, Refs } from 'pretty-format';
-import { PlanNode, QueryPlan } from '../QueryPlan';
+import { PlanNode, QueryPlan } from '@apollo/gateway';
 import { parse, Kind, visit, DocumentNode } from 'graphql';
 
 export default {
@@ -48,7 +48,6 @@ function printNode(
         `Fetch(service: "${node.serviceName}")` +
         ' {' +
         config.spacingOuter +
-        indentationNext +
         (node.requires
           ? printer(
               // this is an array of selections, so we need to make it a proper
@@ -61,8 +60,7 @@ function printNode(
               printer,
             ) +
             ' =>' +
-            config.spacingOuter +
-            indentationNext
+            config.spacingOuter
           : '') +
         printer(
           flattenEntitiesField(parse(node.operation)),

federation-integration-testsuite-js/tsconfig.json

@@ -3,11 +3,11 @@
   "compilerOptions": {
     "rootDir": "./src",
     "outDir": "./dist",
-    "noImplicitAny": false,
-    "strictNullChecks": false,
     "types": ["node", "jest"]
   },
   "include": ["src/**/*"],
   "exclude": ["**/__tests__"],
-  "references": []
+  "references": [
+    { "path": "../gateway-js" }
+  ]
 }