Change default baseBranch in changeset init from master to main

.changeset/funny-cooks-clap.md

@@ -0,0 +1,5 @@
+---
+"@changesets/cli": patch
+---
+
+Change default `baseBranch` in `changeset init` from `master` to `main`.

packages/cli/src/commands/init/__tests__/command.ts

@@ -33,9 +33,9 @@ describe("init", () => {
       true
     );
     await initializeCommand(cwd);
-    expect(await fs.readJson(path.join(cwd, ".changeset/config.json"))).toEqual(
-      defaultWrittenConfig
-    );
+    expect(
+      await fs.readJson(path.join(cwd, ".changeset/config.json"))
+    ).toEqual({ ...defaultWrittenConfig, baseBranch: "main" });
   });
   it("shouldn't overwrite a config if it does exist", async () => {
     const cwd = await f.copy("simple-project");

packages/cli/src/commands/init/index.ts

@@ -7,6 +7,14 @@ import { info, log, warn, error } from "@changesets/logger";
 
 const pkgPath = path.dirname(require.resolve("@changesets/cli/package.json"));
 
+// Modify base branch to "main" without changing defaultWrittenConfig since it also serves as a fallback
+// for config files that don't specify a base branch. Changing that to main would be a breaking change.
+const defaultConfig = JSON.stringify(
+  { ...defaultWrittenConfig, baseBranch: "main" },
+  null,
+  2
+);
+
 export default async function init(cwd: string) {
   const changesetBase = path.resolve(cwd, ".changeset");
 
@@ -33,7 +41,7 @@ export default async function init(cwd: string) {
       }
       await fs.writeFile(
         path.resolve(changesetBase, "config.json"),
-        JSON.stringify(defaultWrittenConfig, null, 2)
+        defaultConfig
       );
     } else {
       warn(
@@ -44,7 +52,7 @@ export default async function init(cwd: string) {
     await fs.copy(path.resolve(pkgPath, "./default-files"), changesetBase);
     await fs.writeFile(
       path.resolve(changesetBase, "config.json"),
-      JSON.stringify(defaultWrittenConfig, null, 2)
+      defaultConfig
     );
 
     log(