Refactor nREPL

nREPL middleware to support refactorings in an editor agnostic way.

The role of this nREPL middleware is to provide refactoring support for clients such as clj-refactor.el. As such, this middleware doesn't perform any refactorings, but returns the information about what needs doing to the client.

Usage

Adding the middleware via Leiningen

Add the following, either in your project's project.clj, or in the :user profile found at ~/.lein/profiles.clj:

:plugins [[refactor-nrepl "1.1.0"]]

Adding the middleware via Boot

Add the following in ~/.boot/profile.boot:

(require 'boot.repl)

(swap! boot.repl/*default-dependencies* conj
       '[refactor-nrepl "1.1.0-SNAPSHOT"])

(swap! boot.repl/*default-middleware* conj
       'refactor-nrepl.middleware/wrap-refactor)

Clojure client

A clojure client is provided for demonstrative purposes, and to make some refactorings available from the REPL.

The refactoring functions are provided as public functions of the refactor-nrepl.client namespace. To work with these functions, you need to connect to a nREPL server which has the refactor-nrepl middleware enabled.

To connect you have two options:

1. Call connect, store the returned transport and pass this to all the refactor functions.
2. Call the refactor functions without a transport, in which case the client will create and store its own transport.

You also need to pass in the path to the file you want to refactor. Pass in a path as you would provide it for slurp. You might also need to pass in more optional or required arguments depending on the the refactor function -- see the documenation of the refactor functions in the refactor-nrepl.client namespace.

Available features

Configure

The configure op takes a single argument opts which is an options map to use for the current session. At present this settings map looks like this:

{
:prefix-rewriting true ; Should clean-ns favor prefix forms in the ns macro?
:debug false ; verbose setting for debugging.
}

The op returns a status of done on success and an error with a message intended for the user in the event of failure.

Find (debug) function invocations

Searches for invocations of predefined list of functions.

Expected input:

• ns-string -- the body of the namespace to work with
• refactor-fn -- value: "find-debug-fns"
• debug-fns -- coma separated list of functions to find invocations of

Returns tuples containing [line-number end-line-number column-number end-column-number fn-name].

The functions to look for should be listed in a comma separated string, either fully qualified or just the function name. If the fully qualified name is provided the middleware will find the invocations of the function if it is required plainly or with an alias. For example:

(:require [clojure.set]
          [secret-santa.util :as u])

However, if only the function name is provided the middleware will find invocations of the function where it is referred. For Example

(:require [clojure.set :refer [difference]]
          [secret-santa.util :refer :all])

In case your client wants to find core clojure functions (for example println) list them only with the function name. A list of functions names to find: "println,pr,prn,secret-santa.util2/foobar,print-let,print.foo/print-let".

Example call from the repl using the clojure client:

(require 'refactor-nrepl.client)
(def tr (refactor-nrepl.client/connect))
(refactor-nrepl.client/remove-debug-invocations :transport tr :file "src/secret_santa/core.clj")

Artifact lookup

This middleware provides operations for obtaining information about artifacts from clojars, or mvn central.

Two ops are available:

artifact-list

Takes no arguments and returns a list of all available artifacts.

artifact-versions

Takes one required argument, artifact which is the full name of the artifact e.g. org.clojure/clojure, and one optional argument force which indicates whether we should force an update of the cached artifacts.

The return value is a list of all the available versions for the artifact.

find-symbol

This op finds occurrences of a single symbol.

find-symbol requires:

file The absolute path to the file containing the symbol to lookup.

dir Only files below this dir will be searched.

ns The ns where the symbol is defined.

name The name of the symbol

line The line number where the symbol occurrs, counting from 1.

column The column number where the symbol occurs, counting from 1.

ignore-errors [optional] if set find symbol carries on even if there is broken namespace which we can not build AST for

The return value is a stream of occurrences under the key occurrence which is an alist like this:

(:line-beg 5 :line-end 5 :col-beg 19 :col-end 26 :name a-name :file \"/aboslute/path/to/file.clj\" :match (fn-name some args))

When the final occurrence has been sent a final message is sent with count, indicating the total number of matches, and status done.

Clients are advised to set ignore-errors on only for find usages as the rest of the operations built on find-symbol supposed to modify the project as well therefore can be destructive if some namespaces can not be analyzed.

find usages (application of find symbols)

Finds occurrences of symbols like defs and defns both where they are defined (if available) and where they are used and prints them.

Example call from the repl:

(refactor-nrepl.client/find-symbol :ns 'leiningen.gargamel :name "gargamel-changelog")

rename symbols (application of find symbols)

Finds and renames occurrences of symbols like defs and defns both where they are defined -- if it makes sense -- and where they are used. Uses the same backend function: find symbols. Replacing the occurrences is implemented in the client.

(refactor-nrepl.client/rename-symbol :ns 'leiningen.gargamel :name "gargamel-changelog" :new-name "garg-cl")

clean-ns

The clean-ns op will perform the following cleanups on an ns form:

• Eliminate :use clauses
• Sort required libraries, imports and vectors of referred symbols
• Rewrite to favor prefix form, e.g. [clojure [string test]] instead of two separate libspecs
• Raise errors if any inconsistencies are found (e.g. a libspec with more than one alias.
• Remove any unused namespaces, referred symbols or imported classes.
• Remove any duplication in the :require and :import form.

The clean-ns requires a path which is the absolute path to the file containing the ns to be operated upon.

The return value, ns is the entire (ns ..) form in prestine condition, or nil if nothing was done (so the client doesn't update the timestamp on files when nothing actually needs doing).

Pretty-printing the (ns ..) form is surprisingly difficult. The current implementation just puts stuff on the right line and delegates the actual indentation to the client.

In the event of an error clean-ns will return error which is an error message intended for display to the user.

Warning: The clean -ns op dependes on tools.analyzer to determine which vars in a file are actually being used. This means the code is evaluated and any top-level occurrences of (launch-missiles) should be avoided.

This op can be configured.

resolve-missing

The goal of the op is to provide intelligent suggestions when the user wants to import or require the unresolvable symbol at point.

The op requires symbol which represents a name to look up on the classpath.

The return value candidates is an alist of ((candidate1 . type1) (candidate2 . type2) ...) where type is in #{:type :class :ns} so we can branch on the 3 various way to import. :type means the symbol resolved to a var created by defrecord or deftype, :class also includes interfaces.

hotload-dependency

Loads a new project dependency into the currently active repl.

The op requires coordinates which is a leiningen style dependency.

The return value is a status of done and dependency which is the coordinate vector that was hotloaded, or error when something went wrong.

find-unbound

This op finds available and used local vars in a selected s-expression in a ns on the classpath. In clj-refactor we use this as the underlying op for the extract-function refactoring: any locals available and used will be unbound in case the s-expression is extracted into a first level form therefore these vars need to be listed as parameters for the new function both at the function definition and at the call site.

This op requires file which is the name of the file to work on as well as line and column: the nearest enclosing s-expression will be used to determine the available and used locals. Both line and column start counting at 1.

Return values status of done and unbound which is a list of unbound vars, or error when something went wrong. The returned vars' order is based on the order of their occurrence in the macro expanded s-expression (that means reversed order for threading macros naturally -- compared to what you actually see).

stubs-for-interface

stubs-for-interface takes a single input interface which is a fully qualified symbol which resolves to either an interface or protocol.

The return value is edn and looks like this:

user> (stubs-for-interface {:interface "java.lang.Iterable"})
({:parameter-list "[^java.util.function.Consumer arg0]", :name "forEach"}
 {:parameter-list "[]", :name "iterator"}
 {:parameter-list "[]", :name "spliterator"})

The intended use-case for stubs-for-interface is to provide enough info to create skeleton implementations when implementing e.g. an interface in a defrecord.

extract-definition

extract-definition is based on find-symbol so it takes the same input values. The return value, definition is a string of edn which looks like this:

{:definition {:line-beg 4
              :line-end 4
              :col-beg 9
              :col-end 21
              :name \"another-val\"
              :file \"core.clj\"
              :match \"(let [another-val 321]\"
              :definition \"321\"}
 :occurrences ({:match \"(println my-constant my-constant another-val)))\"
                :file \"core.clj\"
                :name \"another-val\"
                :col-end 50
                :col-beg 38
                :line-end 5
                :line-beg 5})}

The key :definition contains information about the defining form, so the client can delete it.

The key :occurrences is a seq of all occurrences of the symbol which need to be inlined. This means the definition itself is excluded to avoid any special handling by the client.

version

This op returns, version, which is the current version of this project.

warm-ast-cache

Eagerly builds, and caches ASTs for all clojure files in the project. Returns status done on success and stats for the ASTs built: a list of namespace names as the odd members of the list and either 'OK' as the even member or the error message generated when the given namespace was analyzed. For example

'(com.foo "OK" com.bar "OK" com.baz '("error" "Could not resolve var: keyw"))

rename-file-or-dir

The rename-file-or-dir op takes an old-path and a new-path which are absolute paths to a file or directory.

If old-path is a directory, all files, including any non-clj files, are moved to new-path.

The op returns touched which is a list of all files that were affected by the move, and needs to be visited by the client to indent the updated ns form while we await proper pretty printing support in the middleware.

This op can cause serious havoc if it crashes midway through the refactoring. I recommend not running it without first creating a restore point in your version control system.

Errors

The middleware returns errors under one of two keys: :error or :err. The key :error contains an error string which is intended for the end user. The key :err is used for unexpected failures and contains among other things a full stacktrace.

Development with mranderson

mranderson is used to avoid classpath collisions.

To work with mranderson the first thing to do is:

lein do clean, source-deps :prefix-exclusions "[\"classlojure\"]"

this creates the munged local dependencies in target/srcdeps directory

after that you can run your tests or your repl with:

lein with-profile +plugin.mranderson/config repl

lein with-profile +plugin.mranderson/config test

note the plus sign before the leiningen profile.

If you want to use mranderson while developing locally with the repl the source has to be modified in the target/srcdeps directory.

When you want to release locally:

lein with-profile plugin.mranderson/config install

to clojars:

lein with-profile plugin.mranderson/config deploy clojars

Or alternatively run

./build.sh install

./build.sh deploy clojars

build.sh cleans, runs source-deps with the right parameters, runs the tests and then runs the provided lein target.

Changelog

Unreleased

• Make find-symbol able to handle macros

1.1.0

• Add rename-file-or-dir which returns a file or a directory of clj files.
• Add extract-definition which returns enough information to the clien to afford inlining of defs defns and let-bound vars.
• Add stubs-for-interface for creating skeleton interface implementations
• Add warm-ast-cache op for eagerly building, and caching, ASTs of project files

1.0.5

• add 'version' op, which returns the current version of refactor-nrepl to the client.

1.0.4

• fix for clean-ns removing import only used in macro
• fix for clean-ns removes classes used only in typehints
• workaround for analyzer bug which results in wrong filename in var meta
• fix for find-unbound edge cases

1.0.3

• fix problem in clean-ns caused by mranderson (inlining) limitation

1.0.2 (this is broken version, please use 1.0.3!)

• various bugfixes in clean-ns
• improvements on error messages
• fix in find unbound in case of s-expression is inside a macro
• resolve missing works for static method, field and resolve missign will work right after hotload dependency

1.0.1

• throw an error for cljs and cljx file: they are not supported (yet)
• minor refactorings, clean ups
• readme tweaks
• fix for find-unbound does not always figure out the right parameters for new function

1.0.0

• Config setting for clean-ns to not do any prefix rewriting
• Add configure op to set various config opts.
• Remove find referred
• Add hotload-dependency which loads a new project dependency into the repl
• Add caching of ASTs for better performance
• Add resolve-missing which resolves a missing symbol by scanning the classpath
• Add clean-ns which performs various cleanups on the ns form.
• various cleaning and refactoring stuff

0.2.2

• AST creation: analyze-ns instead of plain analyze which also evals the code

0.2.1

• find usages
• rename symbols

0.1.0

• find (debug) invocations
• find referred
• artifact lookup

License

Copyright © 2013-2014 Benedek Fazekas, Magnar Sveen, Alex Baranosky, Lars Andersen

Distributed under the Eclipse Public License, the same as Clojure.