Validate that projects use Changesets CLI v3 and direct Changesets CLI v2 users to changesets/action@v1

.changeset/bright-lions-check.md

@@ -0,0 +1,5 @@
+---
+"@changesets/action": patch
+---
+
+Validate that projects use Changesets CLI v3 and direct Changesets CLI v2 users to `changesets/action@v1`.

src/index.ts

@@ -8,9 +8,14 @@ import {
   getOptionalInput,
   getRequiredInput,
   throwOnRenamedInputs,
+  validateChangesetsCliVersion,
 } from "./utils.ts";
 
 (async () => {
+  // If the user needs to change the cwd, set `working-directory` in the step instead
+  const cwd = process.cwd();
+  await validateChangesetsCliVersion(cwd);
+
   throwOnRenamedInputs({
     publish: "publish-script",
     version: "version-script",
@@ -32,9 +37,6 @@ import {
     );
   }
 
-  // If the user needs to change the cwd, set `working-directory` in the step instead
-  const cwd = process.cwd();
-
   const commitMode = getOptionalInput("commit-mode") ?? "git-cli";
   const prDraft = getOptionalInput("pr-draft");
   if (commitMode !== "git-cli" && commitMode !== "github-api") {

src/pack/index.ts

@@ -7,6 +7,7 @@ import {
   downloadArtifact,
   execChangesetsCli,
   getOptionalInput,
+  validateChangesetsCliVersion,
 } from "../utils.ts";
 
 try {
@@ -16,10 +17,12 @@ try {
 }
 
 async function main() {
-  const publishPlanArtifactId = getOptionalInput("publish-plan-artifact-id");
-
   // If the user needs to change the cwd, set `working-directory` in the step instead
   const cwd = process.cwd();
+  await validateChangesetsCliVersion(cwd);
+
+  const publishPlanArtifactId = getOptionalInput("publish-plan-artifact-id");
+
   const tmpDir = process.env.RUNNER_TEMP ?? (await fs.realpath(os.tmpdir()));
   const outDir = path.join(tmpDir, `changeset-pack-${Date.now()}`);
 

src/publish/index.ts

@@ -7,6 +7,7 @@ import {
   downloadArtifact,
   getOptionalInput,
   getRequiredInput,
+  validateChangesetsCliVersion,
 } from "../utils.ts";
 
 try {
@@ -16,6 +17,10 @@ try {
 }
 
 async function main() {
+  // If the user needs to change the cwd, set `working-directory` in the step instead
+  const cwd = process.cwd();
+  await validateChangesetsCliVersion(cwd);
+
   const githubToken = getRequiredInput("github-token");
   const script = getOptionalInput("script");
   const packDirArtifactId = getOptionalInput("pack-dir-artifact-id");
@@ -30,9 +35,6 @@ async function main() {
     );
   }
 
-  // If the user needs to change the cwd, set `working-directory` in the step instead
-  const cwd = process.cwd();
-
   // NOTE: Always use API mode here as publish does not need a commit-mode.
   const github = new GitHub({ cwd, githubToken, commitMode: "github-api" });
 

src/run.test.ts

@@ -21,10 +21,8 @@ vi.mock("@actions/github", () => ({
     graphql: mockedGraphql,
   }),
 }));
-vi.mock("@actions/core", async (importOriginal) => ({
-  ...(await importOriginal<typeof import("@actions/core")>()),
-  warning: vi.fn(),
-}));
+vi.mock("@actions/core", { spy: true });
+const mockedWarning = vi.mocked(core.warning);
 vi.mock("@changesets/ghcommit");
 
 let mockedGithubMethods = {
@@ -126,7 +124,7 @@ describe("publish", () => {
     });
 
     expect(result).toEqual({ published: false, exitCode: 0 });
-    expect(core.warning).toHaveBeenCalledWith(
+    expect(mockedWarning).toHaveBeenCalledWith(
       expect.stringContaining(
         "GitHub releases and git tags cannot be created without this output",
       ),

src/select-mode/index.ts

@@ -4,7 +4,7 @@ import path from "node:path";
 import artifact from "@actions/artifact";
 import * as core from "@actions/core";
 import readChangesetState from "../readChangesetState.ts";
-import { execChangesetsCli } from "../utils.ts";
+import { execChangesetsCli, validateChangesetsCliVersion } from "../utils.ts";
 
 type ModeResult =
   | {
@@ -27,7 +27,10 @@ try {
 }
 
 async function main() {
-  const result = await getMode();
+  const cwd = process.cwd();
+  await validateChangesetsCliVersion(cwd);
+
+  const result = await getMode(cwd);
   core.setOutput("mode", result.mode);
   if (result.mode === "publish") {
     const publishPlanArtifact = await artifact.uploadArtifact(
@@ -48,8 +51,8 @@ async function main() {
   }
 }
 
-async function getMode(): Promise<ModeResult> {
-  const { changesets } = await readChangesetState();
+async function getMode(cwd: string): Promise<ModeResult> {
+  const { changesets } = await readChangesetState(cwd);
 
   if (changesets.length > 0) {
     const hasNonEmptyChangesets = changesets.some(
@@ -61,7 +64,6 @@ async function getMode(): Promise<ModeResult> {
     return { mode: "none" };
   }
 
-  const cwd = process.cwd();
   const publishPlanPath = path.join(
     process.env.RUNNER_TEMP ?? (await fs.realpath(os.tmpdir())),
     `changeset-publish-plan-${Date.now()}`,

src/utils.test.ts

@@ -1,5 +1,11 @@
+import { createFixture } from "fs-fixture";
 import { expect, test } from "vitest";
-import { BumpLevels, getChangelogEntry, sortTheThings } from "./utils.ts";
+import {
+  BumpLevels,
+  getChangelogEntry,
+  sortTheThings,
+  validateChangesetsCliVersion,
+} from "./utils.ts";
 
 let changelog = `# @keystone-alpha/email
 
@@ -100,3 +106,49 @@ test("it sorts the things right", () => {
   ];
   expect(things.sort(sortTheThings)).toMatchSnapshot();
 });
+
+test("throws when the project declares Changesets CLI v2", async () => {
+  await using fixture = await createFixture({
+    "package.json": JSON.stringify({
+      name: "project",
+      devDependencies: { "@changesets/cli": "^2.29.7" },
+    }),
+    "package-lock.json": "",
+  });
+
+  await expect(validateChangesetsCliVersion(fixture.path)).rejects.toThrow(
+    "This version of the Changesets action is designed to work with Changesets CLI v3. Changesets CLI v2 is not supported; use Changesets action v1 instead, which is compatible with CLI v2.",
+  );
+});
+
+test("accepts a Changesets CLI v3 contract without an installed CLI", async () => {
+  await using fixture = await createFixture({
+    "package.json": JSON.stringify({
+      name: "project",
+      devDependencies: { "@changesets/cli": "^3.0.0" },
+    }),
+    "package-lock.json": "",
+  });
+
+  await expect(
+    validateChangesetsCliVersion(fixture.path),
+  ).resolves.toBeUndefined();
+});
+
+test("throws when the project has Changesets CLI v2 installed", async () => {
+  await using fixture = await createFixture({
+    "package.json": JSON.stringify({
+      name: "project",
+      devDependencies: { "@changesets/cli": "^3.0.0" },
+    }),
+    "package-lock.json": "",
+    "node_modules/@changesets/cli/package.json": JSON.stringify({
+      name: "@changesets/cli",
+      version: "2.29.7",
+    }),
+  });
+
+  await expect(validateChangesetsCliVersion(fixture.path)).rejects.toThrow(
+    "This version of the Changesets action is designed to work with Changesets CLI v3. Changesets CLI v2 is not supported; use Changesets action v1 instead, which is compatible with CLI v2.",
+  );
+});

src/utils.ts

@@ -10,6 +10,8 @@ import {
   type ExecOutput,
 } from "@actions/exec";
 import { getPackages, type Package } from "@manypkg/get-packages";
+import major from "semver/functions/major.js";
+import subset from "semver/ranges/subset.js";
 
 const require = createRequire(import.meta.url);
 
@@ -154,6 +156,55 @@ export function throwOnRenamedInputs(renames: Record<string, string>) {
   }
 }
 
+const changesetsCliCompatibilityError =
+  "This version of the Changesets action is designed to work with Changesets CLI v3. " +
+  "Changesets CLI v2 is not supported; use Changesets action v1 instead, which is compatible with CLI v2.";
+
+export async function validateChangesetsCliVersion(cwd: string) {
+  const { rootPackage } = await getPackages(cwd);
+  const packageJson = rootPackage?.packageJson;
+  const declaredVersion =
+    packageJson?.devDependencies?.["@changesets/cli"] ??
+    packageJson?.dependencies?.["@changesets/cli"];
+
+  if (typeof declaredVersion === "string") {
+    const range = declaredVersion.startsWith("workspace:")
+      ? declaredVersion.slice("workspace:".length)
+      : declaredVersion;
+
+    let isV2 = false;
+
+    try {
+      isV2 = subset(range, ">=2.0.0-0 <3.0.0-0", {
+        includePrerelease: true,
+      });
+    } catch {
+      // it could be a non-semver protocol
+    }
+
+    if (isV2) {
+      throw new Error(changesetsCliCompatibilityError);
+    }
+  }
+
+  let cliPackageJson;
+
+  try {
+    cliPackageJson = require(
+      require.resolve("@changesets/cli/package.json", { paths: [cwd] }),
+    );
+  } catch {
+    return;
+  }
+
+  if (
+    typeof cliPackageJson.version === "string" &&
+    major(cliPackageJson.version) === 2
+  ) {
+    throw new Error(changesetsCliCompatibilityError);
+  }
+}
+
 function resolveChangesetsCli(cwd: string) {
   return require.resolve("@changesets/cli/bin.js", {
     paths: [cwd],

src/version/index.ts

@@ -1,7 +1,11 @@
 import * as core from "@actions/core";
 import { GitHub } from "../github.ts";
 import { runVersion } from "../run.ts";
-import { getOptionalInput, getRequiredInput } from "../utils.ts";
+import {
+  getOptionalInput,
+  getRequiredInput,
+  validateChangesetsCliVersion,
+} from "../utils.ts";
 
 try {
   await main();
@@ -10,6 +14,10 @@ try {
 }
 
 async function main() {
+  // If the user needs to change the cwd, set `working-directory` in the step instead
+  const cwd = process.cwd();
+  await validateChangesetsCliVersion(cwd);
+
   const githubToken = getRequiredInput("github-token");
   const script = getOptionalInput("script");
   const commitMessage = getRequiredInput("commit-message");
@@ -27,9 +35,6 @@ async function main() {
     throw new Error(`Invalid commit-mode input: ${commitMode}`);
   }
 
-  // If the user needs to change the cwd, set `working-directory` in the step instead
-  const cwd = process.cwd();
-
   const github = new GitHub({
     cwd,
     githubToken,