feat: expect-patch flag

README.md

@@ -229,6 +229,10 @@ Run `patch-package` without arguments to apply all patches in your project.
 
   Specify the name for the directory in which the patch files are located
 
+- `--expect-patch`
+
+  Prints error when no patches happen. Best combined with `--error-on-fail` (enabled by default on CI).
+
 #### Notes
 
 To apply patches individually, you may use `git`:

integration-tests/expect-patch/__snapshots__/expect-patch.test.ts.snap

@@ -0,0 +1,29 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`Test expect-patch: 00: expect-patch flag prints an error message and by default does not fail 1`] = `
+"SNAPSHOT: expect-patch flag prints an error message and by default does not fail
+patch-package 0.0.0
+Applying patches...
+No patch files found
+---
+patch-package finished with 1 error(s).
+END SNAPSHOT"
+`;
+
+exports[`Test expect-patch: 01: expect-patch is silent when patches happen 1`] = `
+"SNAPSHOT: expect-patch is silent when patches happen
+patch-package 0.0.0
+Applying patches...
+[email protected] ✔
+END SNAPSHOT"
+`;
+
+exports[`Test expect-patch: 02: expect-patch flag produces error for error-on-fail flag 1`] = `
+"SNAPSHOT: expect-patch flag produces error for error-on-fail flag
+patch-package 0.0.0
+Applying patches...
+No patch files found
+---
+patch-package finished with 1 error(s).
+END SNAPSHOT"
+`;

integration-tests/expect-patch/expect-patch.sh

@@ -0,0 +1,30 @@
+# make sure errors stop the script
+set -e
+
+echo "add patch-package"
+yarn add $1
+alias patch-package=./node_modules/.bin/patch-package
+
+export NODE_ENV="development"
+export CI="true"
+
+echo "SNAPSHOT: expect-patch flag prints an error message and by default does not fail"
+if ! patch-package --expect-patch;
+then
+  exit 1
+fi
+echo "END SNAPSHOT"
+
+echo "SNAPSHOT: expect-patch is silent when patches happen"
+if ! patch-package --expect-patch --patch-dir patches-custom;
+then
+  exit 1
+fi
+echo "END SNAPSHOT"
+
+echo "SNAPSHOT: expect-patch flag produces error for error-on-fail flag"
+if patch-package --expect-patch --error-on-fail;
+then
+  exit 1
+fi
+echo "END SNAPSHOT"

integration-tests/expect-patch/expect-patch.test.ts

@@ -0,0 +1,5 @@
+import { runIntegrationTest } from "../runIntegrationTest"
+runIntegrationTest({
+  projectName: "expect-patch",
+  shouldProduceSnapshots: true,
+})

integration-tests/expect-patch/package.json

@@ -0,0 +1,11 @@
+{
+  "name": "expect-patch",
+  "version": "1.0.0",
+  "description": "integration test for patch-package",
+  "main": "index.js",
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "left-pad": "^1.3.0"
+  }
+}

integration-tests/expect-patch/patches-custom/left-pad+1.3.0.patch

@@ -0,0 +1,13 @@
+diff --git a/node_modules/left-pad/index.js b/node_modules/left-pad/index.js
+index 26f73ff..60f3f56 100644
+--- a/node_modules/left-pad/index.js
++++ b/node_modules/left-pad/index.js
+@@ -4,7 +4,7 @@
+      * To Public License, Version 2, as published by Sam Hocevar. See
+      * http://www.wtfpl.net/ for more details. */
+ 'use strict';
+-module.exports = leftPad;
++module.exports = patch-package;
+
+ var cache = [
+   '',

integration-tests/expect-patch/yarn.lock

@@ -0,0 +1,8 @@
+# THIS IS AN AUTOGENERATED FILE. DO NOT EDIT THIS FILE DIRECTLY.
+# yarn lockfile v1
+
+
+left-pad@^1.3.0:
+  version "1.3.0"
+  resolved "https://registry.yarnpkg.com/left-pad/-/left-pad-1.3.0.tgz#5b8a3a7765dfe001261dde915589e782f8c94d1e"
+  integrity sha512-XI5MPzVNApjAyhQzphX8BkmKsKUxD4LdyK24iZeQGinBN9yTQT3bFlCBy/aVx2HrNcqQGsdot8ghrjyrvMCoEA==

src/applyPatches.ts

@@ -95,28 +95,34 @@ export function applyPatchesForApp({
   appPath,
   reverse,
   patchDir,
+  expectPatch,
   shouldExitWithError,
   shouldExitWithWarning,
   bestEffort,
 }: {
   appPath: string
   reverse: boolean
   patchDir: string
+  expectPatch: boolean
   shouldExitWithError: boolean
   shouldExitWithWarning: boolean
   bestEffort: boolean
 }): void {
   const patchesDirectory = join(appPath, patchDir)
   const groupedPatches = getGroupedPatches(patchesDirectory)
 
-  if (groupedPatches.numPatchFiles === 0) {
-    console.log(chalk.blueBright("No patch files found"))
-    return
-  }
-
   const errors: string[] = []
   const warnings: string[] = [...groupedPatches.warnings]
 
+  if (groupedPatches.numPatchFiles === 0) {
+    if (expectPatch) {
+      errors.push("No patch files found")
+    } else {
+      console.log(chalk.blueBright("No patch files found"))
+      return
+    }
+  }
+
   for (const patches of Object.values(
     groupedPatches.pathSpecifierToPatchFiles,
   )) {

src/index.ts

@@ -25,6 +25,7 @@ const argv = minimist(process.argv.slice(2), {
     "error-on-warn",
     "create-issue",
     "partial",
+    "expect-patch",
     "",
   ],
   string: ["patch-dir", "append", "rebase"],
@@ -114,11 +115,13 @@ if (argv.version || argv.v) {
       process.env.NODE_ENV === "test"
 
     const shouldExitWithWarning = !!argv["error-on-warn"]
+    const expectPatch = !!argv["expect-patch"]
 
     applyPatchesForApp({
       appPath,
       reverse,
       patchDir,
+      expectPatch,
       shouldExitWithError,
       shouldExitWithWarning,
       bestEffort: argv.partial,
@@ -177,6 +180,15 @@ Usage:
       This option was added to help people using CircleCI avoid an issue around caching
       and patch file updates (https://github.com/ds300/patch-package/issues/37),
       but might be useful in other contexts too.
+
+    ${chalk.bold("--expect-patch")}
+
+      Prints an error if no patch files were found.
+
+      This option works in tandem with ${chalk.bold(
+        "--error-on-fail",
+      )} (enabled by default in CI) to prevent
+      accidental skips due to patch folder was missed or ignored. For example during COPY in Dockerfile, or in .dockerignore.
 
 
   2. Creating patch files