fix: format small agent costs with higher precision instead of rounding to /usr/bin/bash.00

Author: Yetibot

src/yetibot/core/commands/agent.clj

@@ -129,12 +129,21 @@
   []
   "🐵 Bonzi Buddy is swinging into action! Please wait a moment…")
 
+(defn format-cost
+  "Format cost to 4 decimal places if it's less than $0.01, otherwise 2 decimal places."
+  [cost]
+  (cond
+    (nil? cost) "0.00"
+    (zero? cost) "0.00"
+    (< cost 0.01) (format "%.4f" cost)
+    :else (format "%.2f" cost)))
+
 (defn say-final
   "The clean final reply: Gemini's summary plus links to any relevant PRs."
   ([summary pr-urls] (say-final summary pr-urls nil))
   ([summary pr-urls actual-cost]
    (let [cost (or actual-cost (gemini/agent-cost-per-session))
-         footer (format "\n\nSent via %s | Cost: $%.2f" (model) cost)]
+         footer (format "\n\nSent via %s | Cost: $%s" (model) (format-cost cost))]
      (str (if (string/blank? summary) "✅ done." (str "✅ " summary))
           (when (seq pr-urls)
             (str "\n\n🔗 " (string/join "  •  " (distinct pr-urls))))

test/yetibot/core/test/commands/agent.clj

@@ -87,10 +87,27 @@
     (agent/say-final "Added features" nil) => (contains "Sent via gemini-3.1-pro-preview | Cost: $1.00"))
   (fact "say-final accepts actual-cost and prints it correctly in the footer"
     (agent/say-final "Added features" nil 0.12) => (contains "Sent via gemini-3.1-pro-preview | Cost: $0.12")
-    (agent/say-final "Added features" nil 1.234) => (contains "Sent via gemini-3.1-pro-preview | Cost: $1.23"))
+    (agent/say-final "Added features" nil 1.234) => (contains "Sent via gemini-3.1-pro-preview | Cost: $1.23")
+    (agent/say-final "Added features" nil 0.000475) => (contains "Sent via gemini-3.1-pro-preview | Cost: $0.0005")
+    (agent/say-final "Added features" nil 0.004) => (contains "Sent via gemini-3.1-pro-preview | Cost: $0.0040")
+    (agent/say-final "Added features" nil 0.0) => (contains "Sent via gemini-3.1-pro-preview | Cost: $0.00"))
   (fact "say-timeout names the limit"
     (agent/say-timeout 5) => (contains "5 min")))
 
+(facts "about format-cost"
+  (fact "nil or zero costs return 0.00"
+    (agent/format-cost nil) => "0.00"
+    (agent/format-cost 0) => "0.00"
+    (agent/format-cost 0.0) => "0.00")
+  (fact "costs under 0.01 are formatted to 4 decimal places"
+    (agent/format-cost 0.000475) => "0.0005"
+    (agent/format-cost 0.004) => "0.0040"
+    (agent/format-cost 0.0099) => "0.0099")
+  (fact "costs 0.01 or above are formatted to 2 decimal places"
+    (agent/format-cost 0.01) => "0.01"
+    (agent/format-cost 0.12) => "0.12"
+    (agent/format-cost 1.234) => "1.23"))
+
 (facts "about agent limits config defaults"
   (fact "default timeout is 15 minutes"
     (agent/agent-timeout-ms) => 900000)