Experiment with unbranded tcgc

.github/workflows/python-integration.yml

@@ -44,6 +44,12 @@ jobs:
 
       - uses: ./.github/actions/setup-python
 
+      - name: Install pnpm workspace dependencies
+        run: pnpm install --no-frozen-lockfile
+
+      - name: Build http-client-generator-core dependency
+        run: pnpm -r --filter "@typespec/http-client-generator-core..." build
+
       - name: Build and pack http-client-python from PR
         run: |
           cd core/packages/http-client-python

packages/http-client-generator-core/README.md

@@ -0,0 +1,57 @@
+# @typespec/http-client-generator-core
+
+Protocol-agnostic core library for TypeSpec client SDK generation.
+
+## Overview
+
+This package provides the foundational types, interfaces, and infrastructure for generating client SDKs from TypeSpec definitions. It is designed to be **cloud-provider agnostic** — containing no Azure-specific concepts.
+
+Azure-specific functionality (LRO, ARM, Azure Core utilities) is provided by `@azure-tools/typespec-client-generator-core`, which extends this package.
+
+## Architecture
+
+```
+@typespec/http-client-generator-core (this package)
+├── Core type graph (SdkType, SdkModelType, SdkEnumType, etc.)
+├── Client/operation interfaces (SdkClient, SdkClientType, SdkServiceMethod)
+├── HTTP operation mapping (SdkHttpOperation, SdkHttpParameter)
+├── Paging support (SdkPagingServiceMethod, SdkPagingServiceMetadata)
+├── Decorator infrastructure (@clientName, @client, @access, @usage, etc.)
+├── Context management (TCGCContext, SdkContext)
+└── Example types (SdkHttpOperationExample, SdkExampleValue)
+
+@azure-tools/typespec-client-generator-core (Azure extension)
+├── LRO support (SdkLroServiceMethod, SdkLroPagingServiceMethod, SdkLroServiceMetadata)
+├── ARM detection and subscription ID handling
+├── Azure Core utilities (getUnionAsEnum, isPreviewVersion)
+├── Azure-specific defaults and configurations
+└── Re-exports everything from core for backward compatibility
+```
+
+## Key Design Decisions
+
+### Extensible Method Types
+
+The `SdkServiceMethod` union in core includes only `basic` and `paging` variants:
+
+```typescript
+type SdkCoreServiceMethod<T> = SdkBasicServiceMethod<T> | SdkPagingServiceMethod<T>;
+```
+
+The Azure extension adds LRO variants:
+
+```typescript
+type SdkServiceMethod<T> = SdkCoreServiceMethod<T> | SdkLroServiceMethod<T> | SdkLroPagingServiceMethod<T>;
+```
+
+### No Azure Dependencies
+
+This package has **zero** dependencies on:
+- `@azure-tools/typespec-azure-core`
+- `@azure-tools/typespec-azure-resource-manager`
+- Any Azure-specific TypeSpec libraries
+
+### TSP Namespace
+
+Core decorators use `TypeSpec.ClientGenerator.Core` namespace.
+Azure-specific decorators remain in `Azure.ClientGenerator.Core` namespace.

packages/http-client-generator-core/docs/python-emitter-migration.md

@@ -0,0 +1,284 @@
+# Python Emitter Migration Example
+
+This document shows how the Python emitter (`@typespec/http-client-python`) would
+update its imports after the TCGC split.
+
+## Summary
+
+| Import Source | What it provides |
+|---|---|
+| `@typespec/http-client-generator-core` | All core types, context, utilities |
+| `@azure-tools/typespec-client-generator-core` | LRO types + Azure-specific helpers (re-exports core) |
+
+Most files switch entirely to the core package. Only files dealing with LRO or
+Azure-specific helpers need the Azure extension.
+
+---
+
+## emitter.ts
+
+```typescript
+// BEFORE
+import { createSdkContext } from "@azure-tools/typespec-client-generator-core";
+
+// AFTER — createSdkContext is a core function
+import { createSdkContext } from "@typespec/http-client-generator-core";
+```
+
+---
+
+## lib.ts
+
+```typescript
+// BEFORE
+import {
+  SdkContext,
+  SdkType,
+  UnbrandedSdkEmitterOptions,
+} from "@azure-tools/typespec-client-generator-core";
+
+// AFTER — all core types
+import {
+  SdkContext,
+  SdkType,
+  UnbrandedSdkEmitterOptions,
+} from "@typespec/http-client-generator-core";
+```
+
+---
+
+## types.ts
+
+```typescript
+// BEFORE
+import {
+  isHttpMetadata,
+  SdkArrayType,
+  SdkBuiltInType,
+  SdkConstantType,
+  SdkCredentialType,
+  SdkDateTimeType,
+  SdkDictionaryType,
+  SdkDurationType,
+  SdkEndpointType,
+  SdkEnumType,
+  SdkEnumValueType,
+  SdkModelPropertyType,
+  SdkModelType,
+  SdkType,
+  SdkUnionType,
+  UsageFlags,
+} from "@azure-tools/typespec-client-generator-core";
+
+// AFTER — all core types and utilities
+import {
+  isHttpMetadata,
+  SdkArrayType,
+  SdkBuiltInType,
+  SdkConstantType,
+  SdkCredentialType,
+  SdkDateTimeType,
+  SdkDictionaryType,
+  SdkDurationType,
+  SdkEndpointType,
+  SdkEnumType,
+  SdkEnumValueType,
+  SdkModelPropertyType,
+  SdkModelType,
+  SdkType,
+  SdkUnionType,
+  UsageFlags,
+} from "@typespec/http-client-generator-core";
+```
+
+---
+
+## utils.ts
+
+```typescript
+// BEFORE
+import {
+  InitializedByFlags,
+  SdkCredentialParameter,
+  SdkEndpointParameter,
+  SdkHeaderParameter,
+  SdkHttpParameter,
+  SdkMethod,
+  SdkMethodParameter,
+  SdkModelPropertyType,
+  SdkQueryParameter,
+  SdkServiceMethod,
+  SdkServiceOperation,
+  SdkServiceResponseHeader,
+  SdkType,
+} from "@azure-tools/typespec-client-generator-core";
+
+// AFTER — all core types
+import {
+  InitializedByFlags,
+  SdkCredentialParameter,
+  SdkEndpointParameter,
+  SdkHeaderParameter,
+  SdkHttpParameter,
+  SdkMethod,
+  SdkMethodParameter,
+  SdkModelPropertyType,
+  SdkQueryParameter,
+  SdkServiceMethod,
+  SdkServiceOperation,
+  SdkServiceResponseHeader,
+  SdkType,
+} from "@typespec/http-client-generator-core";
+```
+
+---
+
+## http.ts
+
+```typescript
+// BEFORE
+import {
+  getHttpOperationParameter,
+  SdkBasicServiceMethod,
+  SdkBodyParameter,
+  SdkClientType,
+  SdkHeaderParameter,
+  SdkHttpErrorResponse,
+  SdkHttpOperation,
+  SdkHttpOperationExample,
+  SdkHttpResponse,
+  SdkLroPagingServiceMethod,
+  SdkLroServiceMethod,
+  SdkMethodParameter,
+  SdkModelPropertyType,
+  SdkPagingServiceMethod,
+  SdkPathParameter,
+  SdkQueryParameter,
+  SdkServiceMethod,
+  SdkServiceResponseHeader,
+  SdkType,
+  UsageFlags,
+} from "@azure-tools/typespec-client-generator-core";
+
+// AFTER — split between core and azure extension
+import {
+  getHttpOperationParameter,
+  SdkBasicServiceMethod,
+  SdkBodyParameter,
+  SdkClientType,
+  SdkHeaderParameter,
+  SdkHttpErrorResponse,
+  SdkHttpOperation,
+  SdkHttpOperationExample,
+  SdkHttpResponse,
+  SdkMethodParameter,
+  SdkModelPropertyType,
+  SdkPagingServiceMethod,
+  SdkPathParameter,
+  SdkQueryParameter,
+  SdkServiceResponseHeader,
+  SdkType,
+  UsageFlags,
+} from "@typespec/http-client-generator-core";
+// LRO types come from the Azure extension
+import {
+  SdkLroPagingServiceMethod,
+  SdkLroServiceMethod,
+} from "@azure-tools/typespec-client-generator-core";
+// NOTE: SdkServiceMethod is re-exported from azure extension with LRO variants included
+import type { SdkServiceMethod } from "@azure-tools/typespec-client-generator-core";
+```
+
+---
+
+## code-model.ts
+
+```typescript
+// BEFORE
+import {
+  SdkBasicServiceMethod,
+  SdkClientType,
+  SdkCredentialParameter,
+  SdkCredentialType,
+  SdkEndpointParameter,
+  SdkEndpointType,
+  SdkLroPagingServiceMethod,
+  SdkLroServiceMethod,
+  SdkMethodParameter,
+  SdkPagingServiceMethod,
+  SdkServiceMethod,
+  SdkServiceOperation,
+  SdkUnionType,
+  UsageFlags,
+  getCrossLanguagePackageId,
+  isAzureCoreModel,
+} from "@azure-tools/typespec-client-generator-core";
+
+// AFTER — core types from core, Azure-specific from extension
+import {
+  SdkBasicServiceMethod,
+  SdkClientType,
+  SdkCredentialParameter,
+  SdkCredentialType,
+  SdkEndpointParameter,
+  SdkEndpointType,
+  SdkMethodParameter,
+  SdkPagingServiceMethod,
+  SdkServiceOperation,
+  SdkUnionType,
+  UsageFlags,
+  getCrossLanguagePackageId,
+} from "@typespec/http-client-generator-core";
+// Azure-specific: LRO types + Azure model detection
+import {
+  SdkLroPagingServiceMethod,
+  SdkLroServiceMethod,
+  SdkServiceMethod,
+  isAzureCoreModel,
+} from "@azure-tools/typespec-client-generator-core";
+```
+
+---
+
+## package.json changes
+
+```jsonc
+{
+  // BEFORE
+  "peerDependencies": {
+    "@azure-tools/typespec-client-generator-core": ">=0.67.0 <1.0.0"
+  },
+  "devDependencies": {
+    "@azure-tools/typespec-client-generator-core": "~0.67.0"
+  }
+
+  // AFTER
+  "peerDependencies": {
+    "@typespec/http-client-generator-core": "workspace:^",
+    // Still needed for LRO + isAzureCoreModel (optional peer for non-Azure usage)
+    "@azure-tools/typespec-client-generator-core": ">=0.68.0 <1.0.0"
+  },
+  "devDependencies": {
+    "@typespec/http-client-generator-core": "workspace:^",
+    "@azure-tools/typespec-client-generator-core": "~0.68.0"
+  }
+}
+```
+
+---
+
+## Key Observations
+
+1. **4 out of 6 files** can switch entirely to `@typespec/http-client-generator-core`
+   (emitter.ts, lib.ts, types.ts, utils.ts)
+
+2. **2 files** need split imports (http.ts, code-model.ts) because they use:
+   - `SdkLroServiceMethod` / `SdkLroPagingServiceMethod` — Azure LRO extension
+   - `isAzureCoreModel` — Azure-specific helper
+   - `SdkServiceMethod` (the full union including LRO) — Azure extension re-export
+
+3. **Future state**: If/when the Python emitter drops Azure support from its core and
+   moves Azure handling to a separate plugin, it could depend only on the core package.
+
+4. **Backward compat**: The Azure package re-exports everything from core, so existing
+   code continues to work without changes. Migration is opt-in and incremental.