fix: error when command is unknown (#2916)

Since yargs v14, using `.parse(command)` with an unknown command
causes an [error to be thrown](yargs/yargs#1419)
instead of the help text being printed.

One solution is to use `.argv` instead of `.parse(command)` but we
use the `.parse(command)` variant to enable testing as the passed
command is evaluated rather than `process.argv`, which is what happens
when you call `.argv`.

Instead if we detect a error caused by an unknown command, use the parser
to show help instead of version of yargs that had `.parse(command)`
called on it.

packages/ipfs/src/cli/index.js

@@ -18,6 +18,13 @@ module.exports = (command, ctxMiddleware) => {
         .fail((msg, err, yargs) => {
           // Handle yargs errors
           if (msg) {
+            // if the error was caused by an unknown command, the use of `.parse(command)`
+            // below causes printing help to fail: https://github.com/yargs/yargs/issues/1419#issuecomment-527234789
+            // so pass the unadulterated parser in as `yargs` in order to print help successfully
+            if (msg.includes('Unknown argument')) {
+              yargs = parser
+            }
+
             return reject(errCode(new Error(msg), 'ERR_YARGS', { yargs }))
           }
 

packages/ipfs/test/cli/daemon.js

@@ -256,4 +256,13 @@ describe('daemon', () => {
       }
     })
   })
+
+  it('should print help when command is unknown', async function () {
+    this.timeout(100 * 1000)
+
+    const err = await ipfs.fail('derp')
+
+    expect(err.stderr).to.include('Commands:')
+    expect(err.stderr).to.include('Unknown argument: derp')
+  })
 })