`namespace-aliases` could guard against unreadable files

[vemv]

Brief

namespace-aliases i.e. the defn that backs cljr-slash, breaks if there's any .clj file with invalid syntax in a given project.

There's kind of a legitimate use case for .clj files with invalid syntax:

• template files, e.g. moustached clojure
• more importantly, WIP code.

As an aggraviating condition, cljr-slash omits errors, making this issue hard to debug / easy to forget.

So, namespace-aliases could omit files with invalid syntax, instead of throwing exceptions in presence of these files

Steps to reproduce the problem

• echo "totally-invalid(((((((" > src/sample.clj
• invoke refactor-nrepl.ns.libspecs/namespace-aliases

Suggestion

In:

refactor-nrepl/src/refactor_nrepl/ns/libspecs.clj

Line 50 in dbafd6e

{:clj (->> (core/find-in-project (some-fn core/clj-file? core/cljc-file?))

augment the (some-fn ...), with (every-pred readable? (some-fn ...)), where readable? is a defn that tries reading the ns form with tools.reader + tools.namespace.parse, returning false if any exception would have been thrown.

clj-refactor.el and refactor-nrepl version information

Both repos @ master

[bbatsov]

PR welcome!