Introducing @typespec/http-client-js

.chronus/changes/feature-js-emitter-2025-1-27-5-44-11.md

@@ -0,0 +1,7 @@
+---
+changeKind: fix
+packages:
+  - "@typespec/compiler"
+---
+
+Export missing type DiscriminatedUnionLegacy

.chronus/changes/feature-js-emitter-2025-1-27-5-45-10.md

@@ -0,0 +1,7 @@
+---
+changeKind: feature
+packages:
+  - "@typespec/http-client"
+---
+
+Improvements to HttpClient context provider

.chronus/changes/feature-js-emitter-2025-1-27-6-2-18.md

@@ -0,0 +1,7 @@
+---
+changeKind: fix
+packages:
+  - "@typespec/emitter-framework"
+---
+
+Improvements on the TestHarness

.github/CODEOWNERS

@@ -19,6 +19,11 @@
 ######################
 /packages/http-client-python/                @iscai-msft @tadelesh @msyyc
 
+######################
+# JavaScript
+######################
+/packages/http-client-js/                @joheredi
+
 ######################
 # Emiter Shared
 ######################

.prettierignore

@@ -61,5 +61,12 @@ packages/http-client-csharp/generator/TestProjects/**/tspCodeModel.json
 packages/http-client-java/generator/http-client-generator-test/src/main/**/*.json
 packages/http-client-java/generator/http-client-generator-clientcore-test/src/main/**/*.json
 
+# auto generated http-client-js files
+packages/http-client-js/test/e2e/generated/
+
+# built test files for http-client-js
+packages/http-client-js/dist-test
+
+
 .gitattributes
 CODEOWNERS

.prettierrc.json

@@ -21,13 +21,11 @@
       }
     },
     {
-      "files": ["packages/http-client/**/*.tsx"],
-      "options": {
-        "parser": "alloy-ts"
-      }
-    },
-    {
-      "files": ["packages/emitter-framework/**/*.tsx"],
+      "files": [
+        "packages/http-client-js/**/*.tsx",
+        "packages/http-client/**/*.tsx",
+        "packages/emitter-framework/**/*.tsx"
+      ],
       "options": {
         "parser": "alloy-ts"
       }

cspell.yaml

@@ -279,6 +279,8 @@ ignorePaths:
   - packages/compiler/test/formatter/scenarios/**
   - packages/http-client-java/generator/http-client-generator-test/**
   - packages/http-client-java/generator/http-client-generator-clientcore-test/**
+  - packages/http-client-js/test/e2e/**
+  - packages/http-client-js/sample/**
   - pnpm-lock.yaml
   - "**/*.mp4"
   - "**/*.plist"

eng/common/config/area.ts

@@ -18,6 +18,7 @@ export const AreaPaths: Record<keyof typeof AreaLabels, string[]> = {
   "emitter:client:csharp": ["packages/http-client-csharp/"],
   "emitter:client:java": ["packages/http-client-java/"],
   "emitter:client:python": ["packages/http-client-python/"],
+  "emitter:client:js": ["packages/http-client-js/"],
   "emitter:graphql": ["packages/graphql/"],
   "emitter:json-schema": ["packages/json-schema/"],
   "emitter:protobuf": ["packages/protobuf/"],

eng/common/config/labels.ts

@@ -63,6 +63,10 @@ export const AreaLabels = defineLabels({
     color: "e1b300",
     description: "Issue for the Python client emitter: @typespec/http-client-python",
   },
+  "emitter:client:js": {
+    color: "e1b300",
+    description: "Issue for the JavaScript client emitter: @typespec/http-client-js",
+  },
   "emitter:graphql": {
     color: "957300",
     description: "Issues for @typespec/graphql emitter",

eslint.config.js

@@ -120,6 +120,7 @@ const testFilesConfig = tsEslint.config({
 const jsxFilesConfig = tsEslint.config({
   files: ["**/*.tsx"],
   plugins: { "react-hooks": reactHooks },
+  ignores: ["**/packages/http-client-js/**/*"],
   rules: {
     "react-hooks/rules-of-hooks": "error",
     "react-hooks/exhaustive-deps": "warn",
@@ -138,6 +139,7 @@ export default tsEslint.config(
   {
     ignores: [
       "**/dist/**/*",
+      "**/dist-test/**/*",
       "**/.temp/**/*",
       "**/temp/**/*",
       "**/generated-defs/*",
@@ -146,6 +148,8 @@ export default tsEslint.config(
       "**/.docusaurus/**/*",
       "website/src/assets/**/*",
       "packages/compiler/templates/**/*", // Ignore the templates which might have invalid code and not follow exactly our rules.
+      "packages/http-client-js/test/e2e/generated", // Ignore the generated http client
+      "packages/http-client-js/sample/output/**/*", // Ignore the generated http client
       "**/venv/**/*", // Ignore python virtual env
       "**/.vscode-test-web/**/*", // Ignore VSCode test web project
       // TODO: enable

packages/compiler/src/core/helpers/index.ts

@@ -1,4 +1,8 @@
-export { DiscriminatedUnion, getDiscriminatedUnion } from "./discriminator-utils.js";
+export {
+  DiscriminatedUnion,
+  DiscriminatedUnionLegacy,
+  getDiscriminatedUnion,
+} from "./discriminator-utils.js";
 export { getLocationContext } from "./location-context.js";
 export * from "./operation-utils.js";
 export * from "./path-interpolation.js";

packages/compiler/src/experimental/typekit/kits/model.ts

@@ -105,6 +105,17 @@ export interface ModelKit {
     model: Model,
     options?: { includeExtended?: boolean },
   ): RekeyableMap<string, ModelProperty>;
+  /**
+   * Get the record representing additional properties, if there are additional properties.
+   * This method checks for additional properties in the following cases:
+   * 1. If the model is a Record type.
+   * 2. If the model extends a Record type.
+   * 3. If the model spreads a Record type.
+   *
+   * @param model The model to get the additional properties type of.
+   * @returns The record representing additional properties, or undefined if there are none.
+   */
+  getAdditionalPropertiesRecord(model: Model): Model | undefined;
 }
 
 interface TypekitExtension {
@@ -198,9 +209,31 @@ defineKit<TypekitExtension>({
           base = base.baseModel;
         }
       }
-
       // TODO: Add Spread?
       return properties;
     },
+    getAdditionalPropertiesRecord(model) {
+      // model MyModel is Record<> {} should be model with additional properties
+      if (this.model.is(model) && model.sourceModel && this.record.is(model.sourceModel)) {
+        return model.sourceModel;
+      }
+
+      // model MyModel extends Record<> {} should be model with additional properties
+      if (model.baseModel && this.record.is(model.baseModel)) {
+        return model.baseModel;
+      }
+
+      // model MyModel { ...Record<>} should be model with additional properties
+      const spread = this.model.getSpreadType(model);
+      if (spread && this.model.is(spread) && this.record.is(spread)) {
+        return spread;
+      }
+
+      if (model.baseModel) {
+        return this.model.getAdditionalPropertiesRecord(model.baseModel);
+      }
+
+      return undefined;
+    },
   },
 });

packages/emitter-framework/package.json

@@ -6,6 +6,8 @@
   "scripts": {
     "build-src": "babel src -d dist/src --extensions .ts,.tsx",
     "build": "tsc -p . && npm run build-src",
+    "clean": "rimraf ./dist",
+    "format": "prettier . --write",
     "watch-src": "babel src -d dist/src --extensions .ts,.tsx --watch",
     "watch-tsc": "tsc -p . --watch",
     "watch": "concurrently --kill-others \"npm run watch-tsc\" \"npm run watch-src\"",

packages/emitter-framework/src/testing/scenario-test/harness.ts

@@ -271,36 +271,34 @@ function parseScenario(
   );
 
   for (const line of rawLines) {
-    if (line.startsWith("```")) {
-      if (currentCodeBlock) {
-        // Close the code block
-        scenario.lines.push(currentCodeBlock);
-        if (!isTestCodeBlock(currentCodeBlock)) {
-          scenario.specBlock.content = currentCodeBlock.content;
-        } else {
-          for (const [template, fn] of Object.entries(outputCodeBlockTypes)) {
-            const templateRegex = new RegExp(
-              "^" + template.replace(/\{(\w+)\}/g, "(?<$1>[^\\s]+)") + "$",
-            );
-
-            const match = currentCodeBlock.heading.match(templateRegex);
-            if (match) {
-              currentCodeBlock.matchedTemplate = {
-                template,
-                fn,
-                namedArgs: match.groups ?? null,
-              };
-              break;
-            }
+    if (line.startsWith("```") && currentCodeBlock) {
+      // Close the code block
+      scenario.lines.push(currentCodeBlock);
+      if (!isTestCodeBlock(currentCodeBlock)) {
+        scenario.specBlock.content = currentCodeBlock.content;
+      } else {
+        for (const [template, fn] of Object.entries(outputCodeBlockTypes)) {
+          const templateRegex = new RegExp(
+            "^" + template.replace(/\{(\w+)\}/g, "(?<$1>[^\\s]+)") + "$",
+          );
+
+          const match = currentCodeBlock.heading.match(templateRegex);
+          if (match) {
+            currentCodeBlock.matchedTemplate = {
+              template,
+              fn,
+              namedArgs: match.groups ?? null,
+            };
+            break;
           }
-          scenario.testBlocks.push(currentCodeBlock);
         }
-        currentCodeBlock = null;
-      } else {
-        const codeBlockKind = line.includes("tsp") || line.includes("typespec") ? "spec" : "test";
-        // Start a new code block
-        currentCodeBlock = { kind: codeBlockKind, heading: line.substring(3), content: [] };
+        scenario.testBlocks.push(currentCodeBlock);
       }
+      currentCodeBlock = null;
+    } else if (line.startsWith("```")) {
+      const codeBlockKind = line.includes("tsp") || line.includes("typespec") ? "spec" : "test";
+      // Start a new code block
+      currentCodeBlock = { kind: codeBlockKind, heading: line.substring(3), content: [] };
     } else if (currentCodeBlock) {
       // Append to code block content
       currentCodeBlock.content.push(line);

packages/emitter-framework/src/typescript/components/interface-declaration.tsx

@@ -1,4 +1,4 @@
-import { Children, code, refkey as getRefkey, mapJoin } from "@alloy-js/core";
+import { Children, refkey as getRefkey, mapJoin } from "@alloy-js/core";
 import * as ts from "@alloy-js/typescript";
 import { Interface, Model, ModelProperty, Operation, RekeyableMap } from "@typespec/compiler";
 import { $ } from "@typespec/compiler/experimental/typekit";
@@ -84,14 +84,13 @@ function getExtendsType(type: Model | Interface): Children | undefined {
 
   const extending: Children[] = [];
 
-  const recordExtends = code`Record<string, unknown>`;
-
   if (type.baseModel) {
     if ($.array.is(type.baseModel)) {
       extending.push(<TypeExpression type={type.baseModel} />);
     } else if ($.record.is(type.baseModel)) {
-      extending.push(recordExtends);
-      // When extending a record we need to override the element type to be unknown to avoid type errors
+      // Here we are in the additional properties land.
+      // Instead of extending we need to create an envelope property
+      // do nothing here.
     } else {
       extending.push(getRefkey(type.baseModel));
     }
@@ -120,11 +119,15 @@ function membersFromType(type: Model | Interface) {
   let typeMembers: RekeyableMap<string, ModelProperty | Operation> | undefined;
   if ($.model.is(type)) {
     typeMembers = $.model.getProperties(type);
-    const spread = $.model.getSpreadType(type);
-    if (spread && $.model.is(spread) && $.record.is(spread)) {
+    const additionalProperties = $.model.getAdditionalPropertiesRecord(type);
+    if (additionalProperties) {
       typeMembers.set(
         "additionalProperties",
-        $.modelProperty.create({ name: "additionalProperties", optional: true, type: spread }),
+        $.modelProperty.create({
+          name: "additionalProperties",
+          optional: true,
+          type: additionalProperties,
+        }),
       );
     }
   } else {

packages/emitter-framework/src/typescript/components/interface-member.tsx

@@ -15,7 +15,7 @@ export function InterfaceMember({ type, optional }: InterfaceMemberProps) {
   const name = namer.getName(type.name, "object-member-getter");
 
   if ($.modelProperty.is(type)) {
-    const optionality = (type.optional ?? optional) ? "?" : "";
+    const optionality = optional === true || type.optional === true ? "?" : "";
 
     if (isNeverType(type.type)) {
       return null;