add change

.chronus/changes/wanl-service-name-2025-1-27-19-40-32.md

@@ -0,0 +1,7 @@
+---
+changeKind: fix
+packages:
+  - "@typespec/openapi3"
+---
+
+Fix bug of unable to use `{service-name}` interpolation for filenames with openapi3-emitter when only one service is defined

packages/openapi3/test/emit-openapi.test.ts

@@ -1,7 +1,5 @@
 import { resolveVirtualPath } from "@typespec/compiler/testing";
 import { describe, expect, it } from "vitest";
-import { EmitterOptions } from "../../compiler/src/config/types.js";
-import { OpenAPI3EmitterOptions } from "../src/lib.js";
 import { worksFor } from "./works-for.js";
 
 describe("Scalar formats of serialized document in YAML", () => {
@@ -119,7 +117,7 @@ describe("Scalar formats of serialized document in YAML", () => {
         expectedOutputFiles: [resolveVirtualPath("AAA.yaml"), resolveVirtualPath("BBB.yaml")],
       },
     ])("$description", async (c: ServiceNameCase) => {
-      const options: OpenAPI3EmitterOptions & EmitterOptions = {
+      const options = {
         "output-file": c.outputFilePattern,
         "emitter-output-dir": "{output-dir}",
       };

website/src/content/docs/docs/handbook/configuration/configuration.mdx

@@ -102,14 +102,14 @@ Here's what would be produced:
 
 #### Built-in variables
 
-| Variable name              | Scope                      | Description                                                                          |
-| -------------------------- | -------------------------- | ------------------------------------------------------------------------------------ |
-| `cwd`                      | \*                         | Points to the current working directory                                              |
-| `project-root`             | \*                         | Points to the the tspconfig.yaml file containing folder.                             |
-| `output-dir`               | emitter options            | Common `output-dir` See [output-dir](#output-dir---configure-the-default-output-dir) |
-| `emitter-name`             | emitter options            | Name of the emitter                                                                  |
-| `service-name`             | service name               | Name of the service                                                                  |
-| `service-name-if-multiple` | service name if multiple   | Name of the service if multiple, undefined for single service                        |
+| Variable name              | Scope                    | Description                                                                          |
+| -------------------------- | ------------------------ | ------------------------------------------------------------------------------------ |
+| `cwd`                      | \*                       | Points to the current working directory                                              |
+| `project-root`             | \*                       | Points to the the tspconfig.yaml file containing folder.                             |
+| `output-dir`               | emitter options          | Common `output-dir` See [output-dir](#output-dir---configure-the-default-output-dir) |
+| `emitter-name`             | emitter options          | Name of the emitter                                                                  |
+| `service-name`             | service name             | Name of the service                                                                  |
+| `service-name-if-multiple` | service name if multiple | Name of the service if multiple, undefined if one                                    |
 
 #### Project Parameters