Anchor package.json files to the package’s root (#6562)

* Anchor files to the package’s root

npm pack bases paths from the `files` array from the package’s
root. This updates yarn pack to behave in the same way.

* Update CHANGELOG.md

Author: tusbar

CHANGELOG.md

@@ -4,15 +4,15 @@ Please add one entry in this file for each change in Yarn's behavior. Use the sa
 
 ## Master
 
-- Run the engines check before showing the UI for `upgrade-interactive`
+- Ensures the engine check is ran before showing the UI for `upgrade-interactive`
 
   [#6536](https://github.com/yarnpkg/yarn/pull/6536) - [**Orta Therox**](https://github.com/orta)
 
-- Restore Node v4 support by downgrading `cli-table3`
+- Restores Node v4 support by downgrading `cli-table3`
 
   [#6535](https://github.com/yarnpkg/yarn/pull/6535) - [**Mark Stacey**](https://github.com/Gudahtt)
 
-- Prevent infinite loop when parsing corrupted lockfile with unterminated string
+- Prevents infinite loop when parsing corrupted lockfiles with unterminated strings
 
   [#4965](https://github.com/yarnpkg/yarn/pull/4965) - [**Ryan Hendrickson**](https://github.com/rhendric)
 
@@ -32,6 +32,10 @@ Please add one entry in this file for each change in Yarn's behavior. Use the sa
 
   [#5322](https://github.com/yarnpkg/yarn/pull/5322) - [**Karolis Narkevicius**](https://twitter.com/KidkArolis)
 
+- Fixes how the `files` property is interpreted to bring it in line with npm
+
+  [#6562](https://github.com/yarnpkg/yarn/pull/6562) - [**Bertrand Marron**](https://github.com/tusbar)
+
 ## 1.12.0
 
 - Adds initial support for PnP on Windows

__tests__/commands/pack.js

@@ -67,6 +67,18 @@ test.concurrent('pack should include all files listed in the files array', (): P
   });
 });
 
+test.concurrent('pack should include files based from the package’s root', (): Promise<void> => {
+  return runPack([], {}, 'files-include-from-root', async (config): Promise<void> => {
+    const {cwd} = config;
+    const files = await getFilesFromArchive(
+      path.join(cwd, 'files-include-from-root-v1.0.0.tgz'),
+      path.join(cwd, 'files-include-from-root-v1.0.0'),
+    );
+    expect(files.indexOf('index.js')).toBeGreaterThanOrEqual(0);
+    expect(files.indexOf('sub/index.js')).toEqual(-1);
+  });
+});
+
 test.concurrent('pack should included globbed files', (): Promise<void> => {
   return runPack([], {}, 'files-glob', async (config): Promise<void> => {
     const {cwd} = config;

__tests__/fixtures/pack/files-include-from-root/index.js

@@ -0,0 +1 @@
+console.log('included');

__tests__/fixtures/pack/files-include-from-root/package.json

@@ -0,0 +1,6 @@
+{
+  "name": "files-include-from-root",
+  "version": "1.0.0",
+  "license": "MIT",
+  "files": ["index.js"]
+}

__tests__/fixtures/pack/files-include-from-root/sub/index.js

@@ -0,0 +1 @@
+console.log('not included');

src/cli/commands/pack.js

@@ -88,7 +88,7 @@ export async function packTarball(
       onlyFiles.map((filename: string): string => `!${filename}`),
       onlyFiles.map((filename: string): string => `!${path.join(filename, '**')}`),
     );
-    const regexes = ignoreLinesToRegex(lines, '.');
+    const regexes = ignoreLinesToRegex(lines, './');
     filters = filters.concat(regexes);
   }