From 44d1e72f3f10ce95a99c3ca026a77b5442e4fcb4 Mon Sep 17 00:00:00 2001
From: Peter Taoussanis <peter@taoensso.com>
Date: Fri, 11 Oct 2024 10:55:31 +0200
Subject: [PATCH] [new] [Signals] Add `with-middleware+`

---
 src/taoensso/encore.cljc         | 15 ++++++++++----
 src/taoensso/encore/signals.cljc | 34 +++++++++++++++++++++-----------
 test/taoensso/encore_tests.cljc  | 11 ++++++++++-
 3 files changed, 44 insertions(+), 16 deletions(-)

diff --git a/src/taoensso/encore.cljc b/src/taoensso/encore.cljc
index 9540767c..2cfe8ecf 100644
--- a/src/taoensso/encore.cljc
+++ b/src/taoensso/encore.cljc
@@ -7102,10 +7102,17 @@
 
   Useful for composing Ring-style middleware fns."
   {:added "Encore v3.106.0 (2024-05-01)"}
-  ([fs           ] (fn [x] (reduce (fn [x f] (or (f x) (reduced nil))) x fs)))
-  ([f1 f2        ] (fn [x] (when-let [x (f1 x)                    ] (f2 x))))
-  ([f1 f2 f3     ] (fn [x] (when-let [x (f1 x), x (f2 x)          ] (f3 x))))
-  ([f1 f2 f3 & fs] (fn [x] (when-let [x (f1 x), x (f2 x), x (f3 x)] ((comp-middleware fs) x)))))
+  ([fs   ] (fn [x] (reduce (fn [x f] (if f (or (f x) (reduced nil)) x)) x fs)))
+  ([f1 f2]
+   (fn [x]
+     (if f1
+       (if f2
+         (when-let [x (f1 x)] (f2 x))
+         (do                  (f1 x)))
+       (if f2 (f2 x) x))))
+
+  ([f1 f2 f3     ] (fn [x] (when-let [x (if f1 (f1 x) x), x (if f2 (f2 x) x)                    ] (if f3 (f3 x) x))))
+  ([f1 f2 f3 & fs] (fn [x] (when-let [x (if f1 (f1 x) x), x (if f2 (f2 x) x), x (if f3 (f3 x) x)] ((comp-middleware fs) x)))))
 
 (comment ((comp-middleware inc inc (fn [_] nil) (fn [_] (throw (Exception. "Foo")))) 0))
 
diff --git a/src/taoensso/encore/signals.cljc b/src/taoensso/encore/signals.cljc
index f0160caf..2201df59 100644
--- a/src/taoensso/encore/signals.cljc
+++ b/src/taoensso/encore/signals.cljc
@@ -1487,7 +1487,7 @@
   Useful for dynamically transforming signals and/or filtering signals
   by signal data/content/etc.
 
-  Re/bind dynamic        value using `with-middleware`, `binding`.
+  Re/bind dynamic        value using `with-middleware`, `with-middleware+`, `binding`.
   Modify  root (default) value using `set-middleware!`.
 
   As with all dynamic Clojure vars, \"binding conveyance\" applies when using
@@ -1547,15 +1547,6 @@
           "Evaluates given form with given `*ctx*` value. See `*ctx*` for details."
           ~'[ctx-val form] `(binding [~'~*ctx* ~~'ctx-val] ~~'form)))))
 
-#?(:clj
-   (defn- api:with-middleware []
-     (let [*middleware* (symbol (str *ns*) "*middleware*")]
-       `(defmacro ~'with-middleware
-          "Evaluates given form with given `*middleware*` value.
-  See `*middleware*` for details."
-          ~'[?middleware-fn form]
-          `(binding [~'~*middleware* ~~'?middleware-fn] ~~'form)))))
-
 #?(:clj
    (defn- api:with-ctx+ []
      (let [*ctx* (symbol (str *ns*) "*ctx*")]
@@ -1570,6 +1561,26 @@
           ~'[update-map-or-fn form]
           `(binding [~'~*ctx* (update-ctx ~'~*ctx* ~~'update-map-or-fn)] ~~'form)))))
 
+#?(:clj
+   (defn- api:with-middleware []
+     (let [*middleware* (symbol (str *ns*) "*middleware*")]
+       `(defmacro ~'with-middleware
+          "Evaluates given form with given `*middleware*` value.
+  See `*middleware*` for details."
+          ~'[?middleware-fn form]
+          `(binding [~'~*middleware* ~~'?middleware-fn] ~~'form)))))
+
+#?(:clj
+   (defn- api:with-middleware+ []
+     (let [*middleware* (symbol (str *ns*) "*middleware*")]
+       `(defmacro ~'with-middleware+
+          "Evaluates given form with composed `*middleware*` value.
+  Same as (with-middleware (comp-middleware *middleware* ?middleware-fn) ...).
+  See `*middleware*` for details."
+          ~'[?middleware-fn form]
+          `(binding [~'~*middleware* (enc/comp-middleware ~'~*middleware* ~~'?middleware-fn)]
+             ~~'form)))))
+
 ;;;;
 
 #?(:clj
@@ -1635,7 +1646,8 @@
 
           ~(api:with-ctx)
           ~(api:with-ctx+)
-          ~(api:with-middleware)))))
+          ~(api:with-middleware)
+          ~(api:with-middleware+)))))
 
 (comment
   ;; See `taoensso.encore-tests.signal-api` ns
diff --git a/test/taoensso/encore_tests.cljc b/test/taoensso/encore_tests.cljc
index 4faddeed..b89dc597 100644
--- a/test/taoensso/encore_tests.cljc
+++ b/test/taoensso/encore_tests.cljc
@@ -985,7 +985,16 @@
      (testing "`xn` short-circuits (skips `x!`)"
        [(is (= ((enc/comp-middleware  inc xn x!)             0) nil))
         (is (= ((enc/comp-middleware [inc xn x!])            0) nil))
-        (is (= ((enc/comp-middleware  inc inc inc inc xn x!) 0) nil))])]))
+        (is (= ((enc/comp-middleware  inc inc inc inc xn x!) 0) nil))])
+
+     (testing "nil fns"
+       [(is (= ((enc/comp-middleware [nil inc nil x2]) 0) 2))
+        (is (= ((enc/comp-middleware nil x2     ) 1) 2))
+        (is (= ((enc/comp-middleware x2  nil    ) 1) 2))
+        (is (= ((enc/comp-middleware x2  nil nil) 1) 2))
+        (is (= ((enc/comp-middleware nil x2  nil) 1) 2))
+        (is (= ((enc/comp-middleware nil nil x2 ) 1) 2))
+        (is (= ((enc/comp-middleware nil x2 nil x2 nil inc) 1) 5))])]))
 
 ;;;; Futures