fix(iis): merge web.config (#1658)

Co-authored-by: Pooya Parsa <pooya@pi0.io>

docs/content/2.deploy/providers/iis.md

@@ -12,8 +12,7 @@ This is an experimental preset.
 
 1. Install [IISnode](https://github.com/azure/iisnode/releases), and the [IIS URL Rewrite Module](https://www.iis.net/downloads/microsoft/url-rewrite).
 2. In IIS, add `.mjs` as a new mime type and set its content type to `application/javascript`.
-3.  Deploy the contents of your `.output` folder to your website in IIS.
-
+3. Deploy the contents of your `.output` folder to your website in IIS.
 
 ## Using IIS directly
 
@@ -23,4 +22,36 @@ If you do not wish to use IISnode, you can use IIS directly.
 
 1. Make sure that [Node.js](https://nodejs.org/en/) is installed on your Windows Server.
 2. Make sure [`HttpPlatformHandler` Module](https://www.iis.net/downloads/microsoft/httpplatformhandler) is installed.
-3.  Copy your `.output` directory into the Windows Server, and create a website on IIS pointing to that exact directory.
+3. Copy your `.output` directory into the Windows Server, and create a website on IIS pointing to that exact directory.
+
+## IIS Config options
+
+::code-group
+
+```ts [nitro.config.ts]
+export default defineNitroConfig({
+  // IIS options default
+  iis: {
+    // merges in a pre-exisiting web.config file to the nitro default file
+    mergeConfig: true,
+    // overrides the default nitro web.config file all together
+    overrideConfig: false,
+  },
+});
+```
+
+```ts [nuxt.config.ts]
+export default defineNuxtConfig({
+  nitro: {
+    // IIS options default
+    iis: {
+      // merges in a pre-exisiting web.config file to the nitro default file
+      mergeConfig: true,
+      // overrides the default nitro web.config file all together
+      overrideConfig: false,
+    },
+  },
+});
+```
+
+::

package.json

@@ -147,7 +147,16 @@
     "typescript": "^5.2.2",
     "unbuild": "^2.0.0",
     "undici": "^5.23.0",
-    "vitest": "^0.34.3"
+    "vitest": "^0.34.3",
+    "xml2js": "^0.6.2"
+  },
+  "peerDependencies": {
+    "xml2js": "^0.6.2"
+  },
+  "peerDependenciesMeta": {
+    "xml2js": {
+      "optional": true
+    }
   },
   "packageManager": "pnpm@8.7.0",
   "engines": {
@@ -163,4 +172,4 @@
       ]
     }
   }
-}
+}

src/presets/iis.ts

@@ -1,5 +1,6 @@
+import { readFile } from "node:fs/promises";
 import { resolve } from "pathe";
-import { writeFile } from "../utils";
+import { resolveFile, writeFile } from "../utils";
 import { defineNitroPreset } from "../preset";
 import type { Nitro } from "../types";
 
@@ -9,14 +10,91 @@ export const iis = defineNitroPreset({
     async compiled(nitro: Nitro) {
       await writeFile(
         resolve(nitro.options.output.dir, "web.config"),
-        iisXmlTemplate()
+        await iisXmlTemplate(nitro)
       );
     },
   },
 });
 
-function iisXmlTemplate() {
-  return `<?xml version="1.0" encoding="UTF-8"?>
+export const iisNode = defineNitroPreset({
+  extends: "node-server",
+  hooks: {
+    async compiled(nitro: Nitro) {
+      await writeFile(
+        resolve(nitro.options.output.dir, "web.config"),
+        await iisnodeXmlTemplate(nitro)
+      );
+
+      await writeFile(
+        resolve(nitro.options.output.dir, "index.js"),
+        "import('./server/index.mjs');"
+      );
+    },
+  },
+});
+
+async function iisnodeXmlTemplate(nitro: Nitro) {
+  const path = resolveFile("web.config", nitro.options.rootDir, ["config"]);
+  const originalString = `<?xml version="1.0" encoding="utf-8"?>
+<configuration>
+  <system.webServer>
+    <webSocket enabled="false" />
+    <handlers>
+      <add name="iisnode" path="index.js" verb="*" modules="iisnode"/>
+    </handlers>
+    <rewrite>
+      <rules>
+        <rule name="NodeInspector" patternSyntax="ECMAScript" stopProcessing="true">
+          <match url="^server\\/debug[\\/]?" />
+        </rule>
+
+        <rule name="StaticContent">
+          <action type="Rewrite" url="public{REQUEST_URI}"/>
+        </rule>
+
+        <rule name="DynamicContent">
+          <conditions>
+            <add input="{REQUEST_FILENAME}" matchType="IsFile" negate="True"/>
+          </conditions>
+          <action type="Rewrite" url="index.js"/>
+        </rule>
+      </rules>
+    </rewrite>
+
+    <security>
+      <requestFiltering>
+        <hiddenSegments>
+          <remove segment="bin"/>
+          <add segment="node_modules"/>
+        </hiddenSegments>
+      </requestFiltering>
+    </security>
+
+    <httpErrors existingResponse="PassThrough" />
+
+    <iisnode watchedFiles="web.config;*.js" node_env="production" debuggingEnabled="true" />
+  </system.webServer>
+</configuration>
+`;
+  if (path !== undefined) {
+    const fileString = await readFile(path, "utf8");
+    const originalWebConfig: Record<string, unknown> =
+      await parseXmlDoc(originalString);
+    const fileWebConfig: Record<string, unknown> =
+      await parseXmlDoc(fileString);
+
+    if (nitro.options.iis.mergeConfig && !nitro.options.iis.overrideConfig) {
+      return buildNewXmlDoc({ ...originalWebConfig, ...fileWebConfig });
+    } else if (nitro.options.iis.overrideConfig) {
+      return buildNewXmlDoc({ ...fileWebConfig });
+    }
+  }
+  return originalString;
+}
+
+async function iisXmlTemplate(nitro: Nitro) {
+  const path = resolveFile("web.config", nitro.options.rootDir, ["config"]);
+  const originalString = `<?xml version="1.0" encoding="UTF-8"?>
 <configuration>
   <system.webServer>
     <handlers>
@@ -31,4 +109,43 @@ function iisXmlTemplate() {
   </system.webServer>
 </configuration>
 `;
+  if (path !== undefined) {
+    const fileString = await readFile(path, "utf8");
+    const originalWebConfig: Record<string, unknown> =
+      await parseXmlDoc(originalString);
+    const fileWebConfig: Record<string, unknown> =
+      await parseXmlDoc(fileString);
+
+    if (nitro.options.iis.mergeConfig && !nitro.options.iis.overrideConfig) {
+      return buildNewXmlDoc({ ...originalWebConfig, ...fileWebConfig });
+    } else if (nitro.options.iis.overrideConfig) {
+      return buildNewXmlDoc({ ...fileWebConfig });
+    }
+  }
+  return originalString;
+}
+
+//  XML Helpers
+export async function parseXmlDoc(
+  xml: string
+): Promise<Record<string, unknown>> {
+  const { Parser } = await import("xml2js");
+
+  if (xml === undefined || !xml) {
+    return {};
+  }
+  const parser = new Parser();
+  let parsedRecord: Record<string, unknown>;
+  parser.parseString(xml, function (_, r) {
+    parsedRecord = r;
+  });
+  return parsedRecord;
+}
+
+export async function buildNewXmlDoc(
+  xmlObj: Record<string, unknown>
+): Promise<string> {
+  const { Builder } = await import("xml2js");
+  const builder = new Builder();
+  return builder.buildObject({ ...xmlObj });
 }

src/presets/index.ts

@@ -26,7 +26,6 @@ export * from "./cleavr";
 export * from "./layer0";
 export * from "./flightcontrol";
 export * from "./lagon";
-export * from "./iis-node";
-export * from "./iis";
+export { iis, iisNode } from "./iis";
 export { _static as static } from "./static";
 export * from "./github-pages";

src/types/nitro.ts

@@ -330,6 +330,12 @@ export interface NitroOptions extends PresetOptions {
     preview: string;
     deploy: string;
   };
+
+  // IIS
+  iis?: {
+    mergeConfig?: boolean;
+    overrideConfig?: boolean;
+  };
 }
 
 declare global {