From fcb4421c8da230b8ccdc81b7c9f9e7a71a28dc9f Mon Sep 17 00:00:00 2001
From: Travis Prescott <tjprescott@users.noreply.github.com>
Date: Fri, 31 Jan 2025 12:56:32 -0800
Subject: [PATCH] `tsp init` to automatically run `tsp install` (#5824)

Close #5766.

Per discussion from https://github.com/microsoft/typespec/pull/5796 and
Teams, this PR:

- automatically runs `tsp install` as part of `tsp init` if the template
created a `package.json` file
- skips running or mentioning `tsp install` if `package.json` is not
created
- does NOT provide a flag for opt in/out
- does NOT provide a confirmation dialogue


![image](https://github.com/user-attachments/assets/53a656d8-c795-419b-92a2-034883a94bcc)
---
 .../tspInitUpdate-2025-0-31-9-41-10.md        |  7 ++++++
 packages/compiler/src/init/init.ts            | 23 +++++++++++++++----
 packages/compiler/src/init/scaffold.ts        |  2 +-
 3 files changed, 27 insertions(+), 5 deletions(-)
 create mode 100644 .chronus/changes/tspInitUpdate-2025-0-31-9-41-10.md

diff --git a/.chronus/changes/tspInitUpdate-2025-0-31-9-41-10.md b/.chronus/changes/tspInitUpdate-2025-0-31-9-41-10.md
new file mode 100644
index 0000000000..1a13083dea
--- /dev/null
+++ b/.chronus/changes/tspInitUpdate-2025-0-31-9-41-10.md
@@ -0,0 +1,7 @@
+---
+changeKind: feature
+packages:
+  - "@typespec/compiler"
+---
+
+`tsp init` will not automatically run `tsp install` if a `package.json` file is created.
\ No newline at end of file
diff --git a/packages/compiler/src/init/init.ts b/packages/compiler/src/init/init.ts
index 4af843d430..de083f6cd3 100644
--- a/packages/compiler/src/init/init.ts
+++ b/packages/compiler/src/init/init.ts
@@ -2,6 +2,8 @@ import { readdir } from "fs/promises";
 import pc from "picocolors";
 import prompts from "prompts";
 import * as semver from "semver";
+import { CliCompilerHost } from "../core/cli/types.js";
+import { installTypeSpecDependencies } from "../core/install.js";
 import { createDiagnostic } from "../core/messages.js";
 import { getBaseFileName, getDirectoryPath } from "../core/path-utils.js";
 import { CompilerHost, Diagnostic, NoTarget, SourceFile } from "../core/types.js";
@@ -10,7 +12,12 @@ import { readUrlOrPath } from "../utils/misc.js";
 import { getTypeSpecCoreTemplates } from "./core-templates.js";
 import { validateTemplateDefinitions, ValidationResult } from "./init-template-validate.js";
 import { EmitterTemplate, InitTemplate, InitTemplateLibrarySpec } from "./init-template.js";
-import { makeScaffoldingConfig, normalizeLibrary, scaffoldNewProject } from "./scaffold.js";
+import {
+  isFileSkipGeneration,
+  makeScaffoldingConfig,
+  normalizeLibrary,
+  scaffoldNewProject,
+} from "./scaffold.js";
 
 export interface InitTypeSpecProjectOptions {
   templatesUrl?: string;
@@ -18,7 +25,7 @@ export interface InitTypeSpecProjectOptions {
 }
 
 export async function initTypeSpecProject(
-  host: CompilerHost,
+  host: CliCompilerHost,
   directory: string,
   options: InitTypeSpecProjectOptions = {},
 ) {
@@ -80,15 +87,23 @@ export async function initTypeSpecProject(
   });
 
   await scaffoldNewProject(host, scaffoldingConfig);
+  const projectJsonCreated = !isFileSkipGeneration(
+    "package.json",
+    scaffoldingConfig.template.files ?? [],
+  );
 
   // eslint-disable-next-line no-console
   console.log("");
-  // eslint-disable-next-line no-console
-  console.log("TypeSpec init completed. You can run `tsp install` now to install dependencies.");
 
   // eslint-disable-next-line no-console
   console.log(pc.green("Project created successfully."));
 
+  if (projectJsonCreated) {
+    // eslint-disable-next-line no-console
+    console.log(pc.green("Installing dependencies..."));
+    await installTypeSpecDependencies(host, directory);
+  }
+
   if (Object.values(emitters).some((emitter) => emitter.message !== undefined)) {
     // eslint-disable-next-line no-console
     console.log(pc.yellow("\nPlease review the following messages from emitters:"));
diff --git a/packages/compiler/src/init/scaffold.ts b/packages/compiler/src/init/scaffold.ts
index 4eb49c83df..1ffc489b9f 100644
--- a/packages/compiler/src/init/scaffold.ts
+++ b/packages/compiler/src/init/scaffold.ts
@@ -97,7 +97,7 @@ export async function scaffoldNewProject(host: CompilerHost, config: Scaffolding
   await writeFiles(host, config);
 }
 
-function isFileSkipGeneration(fileName: string, files: InitTemplateFile[]): boolean {
+export function isFileSkipGeneration(fileName: string, files: InitTemplateFile[]): boolean {
   for (const file of files) {
     if (file.destination === fileName) {
       return file.skipGeneration ?? false;