make dynamic loading conditional on 1.12

Signed-off-by: Sean Corfield <[email protected]>

CHANGELOG.md

@@ -1,6 +1,6 @@
 # Changes
 
-* v0.7.0 in progress
+* v0.7.0 -- 2024-01-13
   * Address [#55](https://github.com/seancorfield/deps-new/issues/55) by adding support for compound template names that can be resolved to git repositories and template paths within them.
 
 * v0.6.0 64e79d1 -- 2023-12-25

README.md

@@ -181,6 +181,12 @@ generate the documentation, e.g.,
   <name>com.acme/cool-lib</name>
   <description>FIXME: my new org.corfield.new/pom project.</description>
   <url>https://github.com/com.acme/cool-lib</url>
+  <licenses>
+    <license>
+      <name>Eclipse Public License</name>
+      <url>http://www.eclipse.org/legal/epl-v10.html</url>
+    </license>
+  </licenses>
 ...
   <scm>
     <url>https://github.com/acme/cool-lib</url>
@@ -207,16 +213,48 @@ if present, uses that template to create a project, in `mynewproject`. Instead o
 could use `-Sdeps` to specify the dependencies needed to make the template available:
 
 ```bash
-clojure -Sdeps '{:deps {com.acme.project/cool-lib COORDINATES}}' -Tnew create :template com.acme.project/cool-lib :name myusername/mynewproject
+clojure -Sdeps '{:deps {io.github.acme/templates COORDINATES}}' -Tnew create :template com.acme.project/cool-lib :name myusername/mynewproject
 ```
 
 The `COORDINATES` could be something like `{:local/root "/path/to/cool-lib"}`
 for a template that exists on the local filesystem, or it could be based on `:git/url`/`:git/sha` etc
 for a template that exists in a `git` repository.
 
+As of v0.7.0, if you are using Clojure 1.12 -- either as the default `:deps` in
+your `deps.edn` file or via an alias, such as `-A:1.12` -- you can use a
+shorter syntax for the template dependency:
+
+```bash
+clojure -A:1.12 -Tnew create :template io.github.acme/templates%com.acme.project/cool-lib :name myusername/mynewproject
+```
+
+`deps-new` will infer a `git` dependency, as `https://github.com/acme/templates`,
+figure out the latest version on the default branch, check that out, and add it
+to the classpath, and then proceed to use `com.acme.project/cool-lib` as above.
+If you want to use a specific tag, you can use `#` to append that to the
+template specification, e.g., `io.github.acme/templates%com.acme.project/cool-lib#v1.2.3`.
+If the repo is structured such that the Clojure root is not the root of the
+repo itself, i.e., you would normally use `:deps/root` in the coordinates, you
+can specify that with an extra `%` in the template specification, after the
+repo and before the actual template name, e.g., `io.github.acme/templates%lib%com.acme.project/cool-lib#v1.2.3`.
+This would be equivalent to `{:deps {io.github.acme/templates {:git/tag "v1.2.3" :deps/root "lib"}}}`
+(which would not be legal without `:git/sha` as well for `-Sdeps` but
+`deps-new` will resolve the tag to a SHA for you).
+
+If your template name matches the `git` "lib" name, you can omit the template
+from the specification, e.g., `io.github.acme/cool-lib` would be treated as
+both the implied `git` repo and also the template name, as if you had specified:
+`io.github.acme/cool-lib%io.github.acme/cool-lib`.
+
+The examples above using `-A:1.12` assume an alias like this in your `deps.edn` file:
+
+```clojure
+  :1.12 {:override-deps {org.clojure/clojure {:mvn/version "1.12.0-alpha5"}}}
+```
+
 > Note: if you are on Windows, read [**Quoting keys and values**](https://clojure.org/reference/deps_and_cli#quoting) in the official **Deps and CLI Reference** documentation to understand how the above command needs to look on Powershell. Or take a look at the [Babashka CLI](#babashka-cli) library support.
 
-> Note: because `deps-new` is based on `tools.build` and uses its file copying functions, the template must ultimately live on the filesystem, so `:local/root` and `git`-based coordinates are supported, but Maven/Clojars coordinates are not.
+> Note: because `deps-new` is based on `tools.build` and uses its file copying functions, the template must ultimately live on the filesystem, so `:local/root` and `git`-based coordinates are supported, **but Maven/Clojars coordinates are not**.
 
 As of v0.6.0, `:src-dirs` can be used to specify a list of
 directories to search for templates, in addition to the classpath.
@@ -305,6 +343,6 @@ $ clj -M:new app --name foo/bar --overwrite delete
 
 # License
 
-Copyright © 2021-2023 Sean Corfield
+Copyright © 2021-2024 Sean Corfield
 
 Distributed under the Eclipse Public License version 1.0.

src/org/corfield/new.clj

@@ -50,6 +50,8 @@
       for `:delete`, to delete it first; if `:overwrite` is `nil`
       or `false`, an existing directory will not be overwritten."
   [opts]
+  ;; try to establish a DynamicClassLoader so that we can load
+  ;; templates onto the classpath (if we're running Clojure 1.12):
   (try
     (let [cl (.getContextClassLoader (Thread/currentThread))]
       (.setContextClassLoader (Thread/currentThread) (clojure.lang.DynamicClassLoader. cl)))

src/org/corfield/new/impl.clj

@@ -3,7 +3,6 @@
 (ns ^:no-doc org.corfield.new.impl
   "The implementation helpers for `org.corfield.new/create`."
   (:require [clojure.java.io :as io]
-            [clojure.repl.deps :as deps]
             [clojure.string :as str]
             [clojure.tools.deps.extensions.git :as git]
             [clojure.tools.build.api :as b]
@@ -16,6 +15,23 @@
 
 (set! *warn-on-reflection* true)
 
+;; Clojure 1.11 compatibility until TDEPS-258 is fixed:
+(declare add-lib say-resolving) ; to quiet the linter!
+(defmacro patch-add-lib []
+  (if (resolve 'clojure.core/*repl*)
+    `(do
+       (def ~'add-lib (requiring-resolve 'clojure.repl.deps/add-lib))
+       (defn ~'say-resolving [repo# tag#]
+         (println "Resolving" repo# "as a git dependency"
+                  (str (when tag# (str "at " tag#))))))
+    `(do ; define these locally as stubs on Clojure 1.11:
+       (def ~(with-meta '*repl* {:dynamic true}) false)
+       (defn ~'add-lib [lib# _coords#]
+         (println "Dynamically adding" lib# "to the classpath requires Clojure 1.12!"))
+       (defn ~'say-resolving [repo# tag#]
+         (println repo# "matches a git dependency but will not be used!")))))
+(patch-add-lib)
+
 (defn- ->ns
   "Given a string or symbol, presumably representing a
   file path, return a string that represents the
@@ -216,13 +232,12 @@
         [git-sha git-dir]
         (get-git-sha (symbol repo) tag)
         _          (when git-sha
-                     (println "Resolving" repo "as a git dependency"
-                              (str (when tag (str "at " tag))))
+                     (say-resolving repo tag)
                      (binding [*repl* true]
-                       (deps/add-lib (symbol repo)
-                                     (cond-> {:git/sha git-sha}
-                                       deps-root
-                                       (assoc :deps/root deps-root)))))
+                       (add-lib (symbol repo)
+                                (cond-> {:git/sha git-sha}
+                                  deps-root
+                                  (assoc :deps/root deps-root)))))
         {:keys [main] :as name-data}
         (deconstruct-project-name (symbol project-name)) ; allow for string or symbol
         target-dir (str (or target-dir main))