fix: ensure newline between npmrc entries (#42)

* fix: ensure newline between npmrc entries

* chore: use file specific newline

Author: marvinhagemeister

src/commands.ts

@@ -2,7 +2,7 @@
 import * as path from "node:path";
 import * as fs from "node:fs";
 import * as kl from "kolorist";
-import { exec, fileExists, JsrPackage } from "./utils";
+import { exec, fileExists, getNewLineChars, JsrPackage } from "./utils";
 import { Bun, getPkgManager, PkgManagerName, YarnBerry } from "./pkg_manager";
 import { downloadDeno, getDenoDownloadUrl } from "./download";
 
@@ -31,7 +31,9 @@ export async function setupNpmRc(dir: string) {
   try {
     let content = await fs.promises.readFile(npmRcPath, "utf-8");
     if (!content.includes("@jsr:registry=")) {
-      content += JSR_NPMRC;
+      const nl = getNewLineChars(content);
+      const spacer = (!content.endsWith(nl)) ? nl : "";
+      content += spacer + JSR_NPMRC;
       await wrapWithStatus(msg, async () => {
         await fs.promises.writeFile(npmRcPath, content);
       });

src/utils.ts

@@ -187,3 +187,11 @@ export async function exec(
     });
   });
 }
+
+export function getNewLineChars(source: string) {
+  var temp = source.indexOf("\n");
+  if (source[temp - 1] === "\r") {
+    return "\r\n";
+  }
+  return "\n";
+}

test/unit.test.ts

@@ -20,4 +20,26 @@ describe("npmrc", () => {
       assert.equal(content.trim(), "@jsr:registry=https://example.com");
     });
   });
+
+  it("adds newline in between entries if necessary", async () => {
+    await runInTempDir(async (dir) => {
+      const npmrc = path.join(dir, ".npmrc");
+      await fs.promises.writeFile(
+        npmrc,
+        "@foo:registry=https://example.com",
+        "utf-8",
+      );
+
+      await setupNpmRc(dir);
+
+      const content = await fs.promises.readFile(npmrc, "utf-8");
+      assert.equal(
+        content.trim(),
+        [
+          "@foo:registry=https://example.com",
+          "@jsr:registry=https://npm.jsr.io",
+        ].join("\n"),
+      );
+    });
+  });
 });