(fix): support running docs dev server on a port (#3657)

* (feat): support running docs dev server on a port

* (fix): package.json

* fix

fern/pages/docs/introduction/development.mdx

@@ -28,7 +28,14 @@ folder and run the following command:
 fern docs dev
 ```
 
-A local preview of your documentation will be available at `http://localhost:3000`.
+A local preview of your documentation will be available at `http://localhost:3000`. 
+
+By default, Fern will pick a port that is available on your computer. If you'd like to customize the port, 
+use the `--port` flag: 
+
+```bash
+fern docs dev --port 3003
+```
 
 </Accordion>
 

packages/cli/cli/package.json

@@ -73,10 +73,12 @@
     "@fern-api/yaml-migrations": "workspace:*",
     "@fern-api/yaml-schema": "workspace:*",
     "@fern-fern/fiddle-sdk": "^0.0.542",
+    "@types/get-port": "^4.2.0",
     "ansi-escapes": "^5.0.0",
     "axios": "^0.28.0",
     "boxen": "^7.0.0",
     "chalk": "^5.0.1",
+    "get-port": "^7.1.0",
     "immer": "^9.0.15",
     "is-ci": "^3.0.1",
     "js-yaml": "^4.1.0",

packages/cli/cli/src/cli.ts

@@ -11,6 +11,7 @@ import { LogLevel, LOG_LEVELS } from "@fern-api/logger";
 import { askToLogin, login } from "@fern-api/login";
 import { loadProject, Project } from "@fern-api/project-loader";
 import { FernCliError } from "@fern-api/task-context";
+import getPort from "get-port";
 import { Argv } from "yargs";
 import { hideBin } from "yargs/helpers";
 import yargs from "yargs/yargs";
@@ -39,6 +40,7 @@ import { writeDefinitionForWorkspaces } from "./commands/write-definition/writeD
 import { FERN_CWD_ENV_VAR } from "./cwd";
 import { rerunFernCliAtVersion } from "./rerunFernCliAtVersion";
 import { isURL } from "./utils/isUrl";
+
 interface GlobalCliOptions {
     "log-level": LogLevel;
 }
@@ -886,22 +888,26 @@ function addDocsPreviewCommand(cli: Argv<GlobalCliOptions>, cliContext: CliConte
     cli.command(
         "docs dev",
         "Run a local development server to preview your docs",
-        (yargs) => {
-            // yargs.option("port", {
-            //     number: true,
-            //     description: "Run the development server on the following port"
-            // }),
-            return yargs;
-        },
-        async () => {
+        (yargs) =>
+            yargs.option("port", {
+                number: true,
+                description: "Run the development server on the following port"
+            }),
+        async (argv) => {
+            let port: number;
+            if (argv.port != null) {
+                port = argv.port;
+            } else {
+                port = await getPort({ port: [3000, 3001, 3002, 3003, 3004, 3005, 3006, 3007, 3008, 3009, 3010] });
+            }
             await previewDocsWorkspace({
                 loadProject: () =>
                     loadProjectAndRegisterWorkspacesWithContext(cliContext, {
                         defaultToAllApiWorkspaces: true,
                         commandLineApiWorkspace: undefined
                     }),
                 cliContext,
-                port: 3000
+                port
             });
         }
     );

packages/cli/mock/package.json

@@ -32,7 +32,7 @@
     "@fern-api/task-context": "workspace:*",
     "@types/lodash-es": "^4.17.12",
     "express": "^4.19.2",
-    "get-port": "7.0.0",
+    "get-port": "^7.1.0",
     "lodash-es": "^4.17.21",
     "url-join": "^5.0.0"
   },

yarn.lock

@@ -3404,6 +3404,7 @@ __metadata:
     "@fern-fern/fiddle-sdk": ^0.0.542
     "@types/axios": ^0.14.0
     "@types/boxen": ^3.0.1
+    "@types/get-port": ^4.2.0
     "@types/is-ci": ^3.0.2
     "@types/jest": ^29.0.3
     "@types/js-yaml": ^4.0.8
@@ -3422,6 +3423,7 @@ __metadata:
     env-cmd: toddbluhm/env-cmd
     esbuild: ^0.15.7
     eslint: ^8.56.0
+    get-port: ^7.1.0
     immer: ^9.0.15
     is-ci: ^3.0.1
     jest: ^29.7.0
@@ -4136,7 +4138,7 @@ __metadata:
     depcheck: ^1.4.6
     eslint: ^8.56.0
     express: ^4.19.2
-    get-port: 7.0.0
+    get-port: ^7.1.0
     jest: ^29.7.0
     lodash-es: ^4.17.21
     organize-imports-cli: ^0.10.0
@@ -7119,6 +7121,15 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@types/get-port@npm:^4.2.0":
+  version: 4.2.0
+  resolution: "@types/get-port@npm:4.2.0"
+  dependencies:
+    get-port: "*"
+  checksum: 0c084e946089d310b2cfe130b0e4b8c25124800dfba069b756a4477a2e9cb9fabf4f5f59747d987492cbf25b72a24692f6bf1aee1fbfdc47411916221075eba3
+  languageName: node
+  linkType: hard
+
 "@types/glob@npm:^8.0.0":
   version: 8.1.0
   resolution: "@types/glob@npm:8.1.0"
@@ -13347,10 +13358,10 @@ env-cmd@toddbluhm/env-cmd:
   languageName: node
   linkType: hard
 
-"get-port@npm:7.0.0":
-  version: 7.0.0
-  resolution: "get-port@npm:7.0.0"
-  checksum: e9087f62d086bbb70f20c0a208e7cac552679c1426e29e0607eb1b8907a5cc4509337d5971b7f635385cd2a773a14cd21b7d9c3254a2eb5ebeaf5f8fde19fb07
+"get-port@npm:*, get-port@npm:^7.1.0":
+  version: 7.1.0
+  resolution: "get-port@npm:7.1.0"
+  checksum: f4d23b43026124007663a899578cc87ff37bfcf645c5c72651e9810ebafc759857784e409fb8e0ada9b90e5c5db089b0ae2f5f6b49fba1ce2e0aff86094ab17d
   languageName: node
   linkType: hard