TSPD exports support (#4700)

.chronus/changes/tspd-exports-support-2024-9-11-17-14-36.md

@@ -0,0 +1,20 @@
+---
+# Change versionKind to one of: internal, fix, dependencies, feature, deprecation, breaking
+changeKind: fix
+packages:
+  - "@typespec/compiler"
+  - "@typespec/events"
+  - "@typespec/http"
+  - "@typespec/json-schema"
+  - "@typespec/library-linter"
+  - "@typespec/openapi"
+  - "@typespec/openapi3"
+  - "@typespec/protobuf"
+  - "@typespec/rest"
+  - "@typespec/sse"
+  - "@typespec/streams"
+  - "@typespec/versioning"
+  - "@typespec/xml"
+---
+
+TSPD exports support

packages/compiler/package.json

@@ -22,6 +22,7 @@
   "tspMain": "lib/std/main.tsp",
   "exports": {
     ".": {
+      "typespec": "./lib/std/main.tsp",
       "types": "./dist/src/index.d.ts",
       "default": "./dist/src/index.js"
     },

packages/events/package.json

@@ -20,7 +20,10 @@
   "main": "dist/src/index.js",
   "tspMain": "lib/main.tsp",
   "exports": {
-    ".": "./dist/src/index.js",
+    ".": {
+      "typespec": "./lib/main.tsp",
+      "default": "./dist/src/index.js"
+    },
     "./testing": "./dist/src/testing/index.js",
     "./experimental": {
       "types": "./dist/src/experimental/index.d.ts",

packages/http/package.json

@@ -22,6 +22,7 @@
   "tspMain": "lib/http.tsp",
   "exports": {
     ".": {
+      "typespec": "./lib/http.tsp",
       "types": "./dist/src/index.d.ts",
       "default": "./dist/src/index.js"
     },

packages/json-schema/package.json

@@ -21,6 +21,7 @@
   "main": "dist/src/index.js",
   "exports": {
     ".": {
+      "typespec": "./lib/main.tsp",
       "types": "./dist/src/index.d.ts",
       "default": "./dist/src/index.js"
     },

packages/library-linter/package.json

@@ -20,6 +20,7 @@
   "main": "dist/src/index.js",
   "exports": {
     ".": {
+      "typespec": "./dist/src/index.js",
       "types": "./dist/src/index.d.ts",
       "default": "./dist/src/index.js"
     },

packages/openapi/package.json

@@ -21,6 +21,7 @@
   "tspMain": "lib/main.tsp",
   "exports": {
     ".": {
+      "typespec": "./lib/main.tsp",
       "types": "./dist/src/index.d.ts",
       "default": "./dist/src/index.js"
     },

packages/openapi3/package.json

@@ -24,6 +24,7 @@
   "tspMain": "lib/main.tsp",
   "exports": {
     ".": {
+      "typespec": "./lib/main.tsp",
       "types": "./dist/src/index.d.ts",
       "default": "./dist/src/index.js"
     },

packages/protobuf/package.json

@@ -20,7 +20,11 @@
   ],
   "main": "dist/src/index.js",
   "exports": {
-    ".": "./dist/src/index.js",
+    ".": {
+      "typespec": "./lib/proto.tsp",
+      "types": "./dist/src/index.d.ts",
+      "default": "./dist/src/index.js"
+    },
     "./testing": "./dist/src/testing/index.js"
   },
   "type": "module",

packages/rest/package.json

@@ -21,6 +21,7 @@
   "tspMain": "lib/rest.tsp",
   "exports": {
     ".": {
+      "typespec": "./lib/rest.tsp",
       "types": "./dist/src/index.d.ts",
       "default": "./dist/src/index.js"
     },

packages/spec-lib/package.json

@@ -17,7 +17,10 @@
   "main": "dist/index.js",
   "tspMain": "lib/lib.tsp",
   "exports": {
-    ".": "./dist/src/index.js"
+    ".": {
+      "typespec": "./lib/lib.tsp",
+      "default": "./dist/src/index.js"
+    }
   },
   "engines": {
     "node": ">=16.0.0"

packages/sse/package.json

@@ -20,7 +20,10 @@
   "main": "dist/src/index.js",
   "tspMain": "lib/main.tsp",
   "exports": {
-    ".": "./dist/src/index.js",
+    ".": {
+      "typespec": "./lib/main.tsp",
+      "default": "./dist/src/index.js"
+    },
     "./testing": "./dist/src/testing/index.js"
   },
   "engines": {

packages/streams/package.json

@@ -21,6 +21,7 @@
   "tspMain": "lib/main.tsp",
   "exports": {
     ".": {
+      "typespec": "./lib/main.tsp",
       "types": "./dist/src/index.d.ts",
       "default": "./dist/src/index.js"
     },

packages/tspd/src/gen-extern-signatures/gen-extern-signatures.ts

@@ -2,32 +2,74 @@ import {
   CompilerHost,
   Decorator,
   Diagnostic,
+  type PackageJson,
   Program,
+  type SourceLocation,
   compile,
   createDiagnosticCollector,
+  createSourceFile,
   getLocationContext,
   getTypeName,
   joinPaths,
   navigateProgram,
   resolvePath,
-  type PackageJson,
 } from "@typespec/compiler";
 import prettier from "prettier";
+import { createDiagnostic } from "../ref-doc/lib.js";
 import { generateSignatureTests, generateSignatures } from "./decorators-signatures.js";
 import { DecoratorSignature } from "./types.js";
 
+function createSourceLocation(path: string): SourceLocation {
+  return { file: createSourceFile("", path), pos: 0, end: 0 };
+}
 export async function generateExternSignatures(
   host: CompilerHost,
   libraryPath: string,
 ): Promise<readonly Diagnostic[]> {
   const diagnostics = createDiagnosticCollector();
   const pkgJson = await readPackageJson(host, libraryPath);
-  if (!pkgJson.tspMain) {
-    throw new Error("Must have a tspMain with decorator declaration.");
+  if (!pkgJson.exports) {
+    return [
+      createDiagnostic({
+        code: "exports-missing",
+        target: createSourceLocation(resolvePath(libraryPath, "package.json")),
+      }),
+    ];
+  }
+
+  const exportsMap: Record<string, string> = {};
+  for (const [key, value] of Object.entries(pkgJson.exports)) {
+    if (typeof value === "object" && "typespec" in value && typeof value.typespec === "string") {
+      exportsMap[key] = resolvePath(libraryPath, value.typespec);
+    }
+  }
+
+  const exports = Object.values(exportsMap);
+  if (exports.length > 0) {
+    diagnostics.pipe(await generateExternSignatureForExports(host, libraryPath, pkgJson, exports));
+  } else {
+    diagnostics.add(
+      createDiagnostic({
+        code: "exports-missing",
+        messageId: "missingCondition",
+        target: createSourceLocation(resolvePath(libraryPath, "package.json")),
+      }),
+    );
   }
 
-  const main = resolvePath(libraryPath, pkgJson.tspMain);
+  return diagnostics.diagnostics;
+}
+
+export async function generateExternSignatureForExports(
+  host: CompilerHost,
+  libraryPath: string,
+  pkgJson: PackageJson,
+  exports: string[],
+): Promise<[undefined, readonly Diagnostic[]]> {
+  const [main, ...additionalImports] = exports;
+  const diagnostics = createDiagnosticCollector();
   const program = await compile(host, main, {
+    additionalImports,
     parseOptions: { comments: true, docs: true },
   });
   const prettierConfig = await prettier.resolveConfig(libraryPath);
@@ -42,7 +84,7 @@ export async function generateExternSignatures(
   for (const [name, content] of Object.entries(files)) {
     await host.writeFile(resolvePath(outDir, name), content);
   }
-  return diagnostics.diagnostics;
+  return [undefined, diagnostics.diagnostics];
 }
 
 async function readPackageJson(host: CompilerHost, libraryPath: string): Promise<PackageJson> {

packages/tspd/src/ref-doc/lib.ts

@@ -3,6 +3,13 @@ import { createTypeSpecLibrary, paramMessage } from "@typespec/compiler";
 export const libDef = {
   name: "@typespec/tspd",
   diagnostics: {
+    "exports-missing": {
+      severity: "error",
+      messages: {
+        default: `exports field is missing in package.json`,
+        missingCondition: `exports field is missing one export with the typespec condition`,
+      },
+    },
     "documentation-missing": {
       severity: "warning",
       messages: {
@@ -22,6 +29,6 @@ export const libDef = {
 } as const;
 
 export const $lib = createTypeSpecLibrary(libDef);
-export const { reportDiagnostic, createStateSymbol } = $lib;
+export const { reportDiagnostic, createStateSymbol, createDiagnostic } = $lib;
 
 export type RefDocLibrary = typeof $lib;

packages/versioning/package.json

@@ -21,6 +21,7 @@
   "tspMain": "lib/main.tsp",
   "exports": {
     ".": {
+      "typespec": "./lib/main.tsp",
       "types": "./dist/src/index.d.ts",
       "default": "./dist/src/index.js"
     },

packages/xml/package.json

@@ -20,7 +20,10 @@
   "main": "dist/src/index.js",
   "tspMain": "lib/main.tsp",
   "exports": {
-    ".": "./dist/src/index.js",
+    ".": {
+      "typespec": "./lib/main.tsp",
+      "default": "./dist/src/index.js"
+    },
     "./testing": "./dist/src/testing/index.js"
   },
   "engines": {