Fix file watcher regression

[ikappaki]

Hi,

could you please consider fix for issue #27.

It is caused by the recent #23 commit which uses a regexp against the modified filename to determine which files are supported to be shown by the browser.

The original commit converted the modified file's Path into an io/file for convenience and then extracted the filename as a String, but the Path to io/file conversion fails on OS X throwing an exception (as shown at the end).

The fix is to retrieve the filename string from the Path directly.

Also, it might be a good idea to have clerk/file-event try and catch any exception thrown instead of silently failing?

error thrown: (is this a bug?)

:error #error {
 :cause No implementation of method: :as-file of protocol: #'clojure.java.io/Coercions found for class: sun.nio.fs.UnixPath
 :via
 [{:type java.lang.IllegalArgumentException
   :message No implementation of method: :as-file of protocol: #'clojure.java.io/Coercions found for class: sun.nio.fs.UnixPath
   :at [clojure.core$_cache_protocol_fn invokeStatic core_deftype.clj 583]}]
 :trace
 [[clojure.core$_cache_protocol_fn invokeStatic core_deftype.clj 583]
  [clojure.java.io$fn__11390$G__11372__11395 invoke io.clj 35]
  [clojure.java.io$file invokeStatic io.clj 424]
  [clojure.java.io$file invoke io.clj 418]
  [nextjournal.clerk$supported_file_QMARK_ invokeStatic NO_SOURCE_FILE 181]
  [nextjournal.clerk$supported_file_QMARK_ invoke NO_SOURCE_FILE 174]
  [nextjournal.clerk$file_event invokeStatic clerk.clj 211]
  [nextjournal.clerk$file_event invoke clerk.clj 209]
  [nextjournal.clerk$serve_BANG_$fn__18760 invoke clerk.clj 289]
  [nextjournal.beholder$fn$reify__6032 onEvent beholder.clj 13]
  [io.methvin.watcher.DirectoryWatcher onEvent DirectoryWatcher.java 352]
  [io.methvin.watcher.DirectoryWatcher watch DirectoryWatcher.java 297]
  [io.methvin.watcher.DirectoryWatcher lambda$watchAsync$0 DirectoryWatcher.java 212]
  [java.util.concurrent.CompletableFuture$AsyncSupply run CompletableFuture.java 1768]
  [java.util.concurrent.CompletableFuture$AsyncSupply exec CompletableFuture.java 1760]
  [java.util.concurrent.ForkJoinTask doExec ForkJoinTask.java 373]
  [java.util.concurrent.ForkJoinPool$WorkQueue topLevelExec ForkJoinPool.java 1182]
  [java.util.concurrent.ForkJoinPool scan ForkJoinPool.java 1655]
  [java.util.concurrent.ForkJoinPool runWorker ForkJoinPool.java 1622]
  [java.util.concurrent.ForkJoinWorkerThread run ForkJoinWorkerThread.java 165]]}

(Tested it to work on both OS X and MS Windows)

Thanks!

[ikappaki]

It appears clojure.java.io/file does not support Paths as an argument to begin with, so original implementation was incorrect trying to coerce Path into a File. It should fail on all architectures, not just OS X.

https://clojure.atlassian.net/browse/CLJ-2333

io/file delegates to the io/Coercions protocol's as-file method for coercing its arguments into a File. It can coerce String, File, URL and URIs by default.

It so happens on my main dev machine I have clj-refactor installed, which injects the refactor-nrepl into the repl, which inlines clj-commans/fs (with MrAnderson) , which extends io/Coercions with Path, and thus how it was tested to work for me in the first place ..., e.g. in my REPL with clj-refactor installed , I get:

user> (:impls clojure.java.io/Coercions)
{nil
 {:as-file #function[clojure.java.io/fn--11402],
  :as-url #function[clojure.java.io/fn--11404]},
 java.lang.String
 {:as-file #function[clojure.java.io/fn--11406],
  :as-url #function[clojure.java.io/fn--11408]},
 java.io.File
 {:as-file #function[clojure.java.io/fn--11410],
  :as-url #function[clojure.java.io/fn--11412]},
 java.net.URL
 {:as-url #function[clojure.java.io/fn--11414],
  :as-file #function[clojure.java.io/fn--11416]},
 java.net.URI
 {:as-url #function[clojure.java.io/fn--11418],
  :as-file #function[clojure.java.io/fn--11420]},
 java.nio.file.Path
 {:as-file
  #function[refactor-nrepl.inlined-deps.fs.v1v6v307.me.raynes.fs/eval2296/fn--2297],
  :as-url
  #function[refactor-nrepl.inlined-deps.fs.v1v6v307.me.raynes.fs/eval2296/fn--2299]}}

I suppose having REPL middleware modifying core behaviour could be considered dangerous, though it happens indirectly byclj-commns/fs. I shall reach out to them to see what they think.

I originally thought clerk/file-event's path was a string and thus the original implementation with passing it to io/file and the unit tests written with strings. I suppose in retrospect I should have checked the path's type. and not relied on the REPL#s behaviour...

Thanks!

[mk]

Thanks for looking into this again and digging so deep to figure out what the problem is. I also do have refactor-clj on the classpath and hence everything was working for me when I tested it.

Will look into setting up a test suite (with a clear separation of the test and dev class paths) soon.