Support @file context in custom command arguments

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 - Recover Anthropic streaming responses interrupted by transient TLS `bad_record_mac` failures.
 - BREAKING: `plugins.install` now appends across config layers. Set `plugins.installMode` to `replace` beside the list to exclude inherited plugins as before.
+- Expand `@file` references in custom-command and parameterized-skill arguments into file content before sending the prompt. #163
 
 ## 0.159.0
 

docs/config/commands.md

@@ -7,7 +7,7 @@ description: "Configure ECA commands: built-in slash commands like /init and /co
 ![](../images/features/commands.png)
 
 You can configure custom command prompts for project, global or via `commands` config pointing to the path of the commands.
-Prompts can use positional variables like `$ARGUMENTS`, `$1`, `$2`, or [named `{{name}}` variables](#frontmatter-description-and-named-arguments), to replace in the prompt during command call.
+Prompts can use positional variables like `$ARGUMENTS`, `$1`, `$2`, or [named `{{name}}` variables](#frontmatter-description-and-named-arguments), to replace in the prompt during command call. File references passed as arguments (for example, `@/workspace/src/app.clj`) include the file content just like they do in a regular chat prompt. Quote arguments that contain spaces.
 
 !!! tip "Skills support arguments too"
 

src/eca/features/commands.clj

@@ -10,6 +10,7 @@
    [eca.features.chat.debug :as f.chat.debug]
    [eca.features.chat.export :as f.chat.export]
    [eca.features.chat.lifecycle :as lifecycle]
+   [eca.features.context :as f.context]
    [eca.features.index :as f.index]
    [eca.features.login :as f.login]
    [eca.features.plugins :as f.plugins]
@@ -339,6 +340,20 @@
                                                   custom-cmds)))]
     (substitute-args raw-content args)))
 
+(defn ^:private file-context-arg [arg]
+  (when (and (string/starts-with? arg "@")
+             (< 1 (count arg)))
+    (f.context/parse-context-reference (subs arg 1))))
+
+(defn ^:private add-file-context [prompt args db]
+  (if-let [contexts-str (some-> (keep file-context-arg args)
+                                (f.context/raw-contexts->refined db)
+                                seq
+                                (f.prompt/contexts-str nil nil))]
+    [{:type :text :text prompt}
+     {:type :text :text contexts-str}]
+    prompt))
+
 (defn ^:private format-tool-permissions [{:keys [toolCall]}]
   (when-let [approval (:approval toolCall)]
     (let [by-default (:byDefault approval)
@@ -1152,7 +1167,7 @@
       ;; else check if a custom command or skill
       (if-let [custom-command-prompt (get-custom-command command args custom-cmds)]
         {:type :send-prompt
-         :prompt custom-command-prompt}
+         :prompt (add-file-context custom-command-prompt args db)}
         (if-let [skill (first (filter #(= command (:name %)) skills))]
           {:type :send-prompt
            :prompt (cond
@@ -1163,7 +1178,7 @@
                      (str "Load skill: " (:name skill))
 
                      (seq args)
-                     (substitute-args (:body skill) args)
+                     (add-file-context (substitute-args (:body skill) args) args db)
 
                      :else
                      (str "Load skill: " (:name skill)))}

src/eca/features/context.clj

@@ -165,20 +165,28 @@
               nil))
           contexts))
 
+(defn parse-context-reference
+  "Parse a path with an optional `:L<start>-L<end>` suffix into a raw context map."
+  [reference]
+  (when (seq reference)
+    (let [[_ path start end] (re-matches #"(.+):L(\d+)-L(\d+)$" reference)
+          path (or path reference)
+          path (if (string/starts-with? path "~")
+                 (str (fs/expand-home path))
+                 path)]
+      (cond-> {:type (if (fs/directory? path) "directory" "file")
+               :path path}
+        (and start end) (assoc :lines-range {:start (parse-long start)
+                                             :end (parse-long end)})))))
+
 (defn contexts-str-from-prompt
   "Extract all contexts (@something) and refine them.
    Parse lines if present in contexts like @/path/to/file:L1-L4"
   [prompt db]
-  (let [ ;; Capture @<path> with optional :L<start>-L<end>
-        context-pattern #"@([/~\.][^\s:]+)(?::L(\d+)-L(\d+))?"
+  (let [;; Capture @<path> with optional :L<start>-L<end>
+        context-pattern #"@([/~\.][^\s:]+(?::L\d+-L\d+)?)"
         matches (re-seq context-pattern prompt)
-        raw-contexts (mapv (fn [[_ path s e]]
-                             (assoc-some {:type (if (fs/directory? path) "directory" "file")
-                                          :path path}
-                                         :lines-range (when (and s e)
-                                                        {:start (Integer/parseInt s)
-                                                         :end   (Integer/parseInt e)})))
-                           matches)]
+        raw-contexts (mapv (comp parse-context-reference second) matches)]
     (when (seq raw-contexts)
       (raw-contexts->refined raw-contexts db))))
 

test/eca/features/chat_test.clj

@@ -1713,6 +1713,9 @@
             :command "login"
             :args ["foo bar" "baz" "qux bla blow"]}
            (#'f.chat/message->decision "/login \"foo bar\" baz \"qux bla blow\"" {} {}))))
+  (testing "quoted file arguments with spaces remain one token"
+    (is (= ["review" "@/dir/My File.clj"]
+           (#'f.chat/tokenize-args "review \"@/dir/My File.clj\""))))
   (with-redefs [f.mcp/all-prompts (constantly [{:name "prompt"
                                                 :server "server"}])]
     (testing "MCP prompt without args"
@@ -2925,4 +2928,3 @@
       (is (= "company-litellm/big"
              (resolve-model nil "main" {:defaultModel "explorer-small"}))))))
 
-

test/eca/features/commands_test.clj

@@ -7,6 +7,7 @@
    [eca.features.chat.export :as f.chat.export]
    [eca.features.commands :as f.commands]
    [eca.features.rules :as f.rules]
+   [eca.features.skills :as f.skills]
    [eca.shared :as shared]
    [eca.test-helper :as h]))
 
@@ -103,6 +104,55 @@
       (is (= "Process one two here"
              (#'f.commands/get-custom-command "test" ["one" "two"] custom))))))
 
+(deftest custom-command-file-context-test
+  (let [tmp-dir (fs/create-temp-dir)]
+    (try
+      (let [command-file (fs/file tmp-dir "review.md")
+            context-file (fs/file tmp-dir "example file.clj")
+            context-path (str (fs/canonicalize context-file))]
+        (spit command-file "Review $1")
+        (spit context-file "(def answer 42)")
+        (let [result (f.commands/handle-command!
+                      "review"
+                      [(str "@" context-path)]
+                      (assoc (command-context "chat-1")
+                             :config {:pureConfig true
+                                      :commands [{:path (str command-file)}]}))]
+          (is (= :send-prompt (:type result)))
+          (is (= (str "Review @" context-path)
+                 (get-in result [:prompt 0 :text])))
+          (is (string/includes? (get-in result [:prompt 1 :text])
+                                (str "<file path=\"" context-path "\">(def answer 42)</file>")))))
+      (testing "an unreadable file argument leaves the expanded prompt unchanged"
+        (let [result (f.commands/handle-command!
+                      "review"
+                      ["@/missing/example.clj"]
+                      (assoc (command-context "chat-1")
+                             :config {:pureConfig true
+                                      :commands [{:path (str (fs/file tmp-dir "review.md"))}]}))]
+          (is (= "Review @/missing/example.clj" (:prompt result)))))
+      (finally
+        (fs/delete-tree tmp-dir)))))
+
+(deftest parameterized-skill-file-context-test
+  (let [tmp-dir (fs/create-temp-dir)]
+    (try
+      (let [context-file (fs/file tmp-dir "example.clj")
+            context-path (str (fs/canonicalize context-file))]
+        (spit context-file "(def answer 42)")
+        (with-redefs [f.skills/all (constantly [{:name "review"
+                                                 :body "Review $1"}])]
+          (let [result (f.commands/handle-command! "review"
+                                                   [(str "@" context-path)]
+                                                   (command-context "chat-1"))]
+            (is (= :send-prompt (:type result)))
+            (is (= (str "Review @" context-path)
+                   (get-in result [:prompt 0 :text])))
+            (is (string/includes? (get-in result [:prompt 1 :text])
+                                  (str "<file path=\"" context-path "\">(def answer 42)</file>"))))))
+      (finally
+        (fs/delete-tree tmp-dir)))))
+
 (deftest substitute-args-test
   (testing "replaces $ARGS with all args joined"
     (is (= "Review https://github.com/org/repo/pull/1"

test/eca/features/context_test.clj

@@ -570,6 +570,22 @@
              :content "Some content"}]
            (f.context/contexts-str-from-prompt "check @/path/to/folder" (h/db)))))))
 
+(deftest parse-context-reference-test
+  (with-redefs [fs/directory? (constantly false)]
+    (is (= {:type "file"
+            :path "/path/to/file"
+            :lines-range {:start 2 :end 4}}
+           (f.context/parse-context-reference "/path/to/file:L2-L4")))
+    (is (= {:type "file"
+            :path (h/file-path "C:\\dir\\file.clj")
+            :lines-range {:start 2 :end 4}}
+           (f.context/parse-context-reference "C:\\dir\\file.clj:L2-L4"))))
+  (testing "expands a leading home directory"
+    (with-redefs [fs/expand-home (constantly (h/file-path "/home/user/notes.md"))
+                  fs/directory? (constantly false)]
+      (is (= {:type "file" :path (h/file-path "/home/user/notes.md")}
+             (f.context/parse-context-reference "~/notes.md"))))))
+
 (deftest raw-contexts->refined-image-test
   (testing "Inline image context is refined into the canonical {:type :image ...} shape"
     (h/reset-components!)