fix: respect .npmrc if already present (#30)

* fix: respect .npmrc if already present

* Update dist file

Co-authored-by: mitchellhamilton <mitchell@hamil.town>

README.md

@@ -104,6 +104,26 @@ jobs:
 
 ```
 
+By default the GitHub Action creates a `.npmrc` file with the following content:
+
+```
+//registry.npmjs.org/:_authToken=${process.env.NPM_TOKEN}
+```
+
+However, if a `.npmrc` file is found, the GitHub Action does not recreate the file. This is useful if you need to configure the `.npmrc` file on your own.
+For example, you can add a step before running the Changesets GitHub Action:
+
+```yml
+- name: Creating .npmrc
+  run: |
+    cat << EOF > "$HOME/.npmrc"
+      email=my@email.com
+      //registry.npmjs.org/:_authToken=$NPM_TOKEN
+    EOF
+  env:
+    NPM_TOKEN: ${{ secrets.NPM_TOKEN }}
+```
+
 #### With version script
 
 If you need to add additional logic to the version command, you can do so by using a version script.

index.ts

@@ -85,10 +85,16 @@ import readChangesets from "@changesets/read";
 
     let workspacesByName = new Map(workspaces.map(x => [x.name, x]));
 
-    fs.writeFileSync(
-      `${process.env.HOME}/.npmrc`,
-      `//registry.npmjs.org/:_authToken=${process.env.NPM_TOKEN}`
-    );
+    let npmrcPath = `${process.env.HOME}/.npmrc`
+    if (fs.existsSync(npmrcPath)) {
+      console.log("Found existing .npmrc file");
+    } else {
+      console.log("No .npmrc file found, creating one");
+      fs.writeFileSync(
+        npmrcPath,
+        `//registry.npmjs.org/:_authToken=${process.env.NPM_TOKEN}`
+      );
+    }
 
     let [publishCommand, ...publishArgs] = inputs.publishScript.split(/\s+/);