From e7a04eb3d22b09a69f439858960638532c931139 Mon Sep 17 00:00:00 2001
From: Leon <29leon42005+github@gmail.com>
Date: Wed, 25 Jun 2025 15:22:21 +0200
Subject: [PATCH] Short-format negative and small numbers in
 energy-distribution-card (#25862)

---
 src/data/energy.ts       | 11 ++++++++---
 test/data/energy.test.ts | 39 +++++++++++++++++++++++++++------------
 2 files changed, 35 insertions(+), 15 deletions(-)

diff --git a/src/data/energy.ts b/src/data/energy.ts
index 0ee60fde90..3510c92125 100644
--- a/src/data/energy.ts
+++ b/src/data/energy.ts
@@ -1114,12 +1114,16 @@ export const formatConsumptionShort = (
   if (!consumption) {
     return `0 ${unit}`;
   }
-  const units = ["kWh", "MWh", "GWh", "TWh"];
+  const units = ["Wh", "kWh", "MWh", "GWh", "TWh"];
   let pickedUnit = unit;
   let val = consumption;
   let unitIndex = units.findIndex((u) => u === unit);
   if (unitIndex >= 0) {
-    while (val >= 1000 && unitIndex < units.length - 1) {
+    while (Math.abs(val) < 1 && unitIndex > 0) {
+      val *= 1000;
+      unitIndex--;
+    }
+    while (Math.abs(val) >= 1000 && unitIndex < units.length - 1) {
       val /= 1000;
       unitIndex++;
     }
@@ -1127,7 +1131,8 @@ export const formatConsumptionShort = (
   }
   return (
     formatNumber(val, hass.locale, {
-      maximumFractionDigits: val < 10 ? 2 : val < 100 ? 1 : 0,
+      maximumFractionDigits:
+        Math.abs(val) < 10 ? 2 : Math.abs(val) < 100 ? 1 : 0,
     }) +
     " " +
     pickedUnit
diff --git a/test/data/energy.test.ts b/test/data/energy.test.ts
index d70ad81593..02d8fe170e 100644
--- a/test/data/energy.test.ts
+++ b/test/data/energy.test.ts
@@ -68,15 +68,18 @@ describe("Energy Short Format Test", () => {
   };
 
   const hass = { locale: defaultLocale } as HomeAssistant;
-  it("Formats", () => {
+  it("No Unit conversion", () => {
+    assert.strictEqual(formatConsumptionShort(hass, 0, "Wh"), "0 Wh");
     assert.strictEqual(formatConsumptionShort(hass, 0, "kWh"), "0 kWh");
     assert.strictEqual(formatConsumptionShort(hass, 0, "GWh"), "0 GWh");
     assert.strictEqual(formatConsumptionShort(hass, 0, "gal"), "0 gal");
 
     assert.strictEqual(
-      formatConsumptionShort(hass, 0.12345, "kWh"),
-      "0.12 kWh"
+      formatConsumptionShort(hass, 10000.12345, "gal"),
+      "10,000 gal"
     );
+
+    assert.strictEqual(formatConsumptionShort(hass, 1.2345, "kWh"), "1.23 kWh");
     assert.strictEqual(
       formatConsumptionShort(hass, 10.12345, "kWh"),
       "10.1 kWh"
@@ -85,6 +88,10 @@ describe("Energy Short Format Test", () => {
       formatConsumptionShort(hass, 500.12345, "kWh"),
       "500 kWh"
     );
+
+    assert.strictEqual(formatConsumptionShort(hass, 10.01, "kWh"), "10 kWh");
+  });
+  it("Upward Unit conversion", () => {
     assert.strictEqual(
       formatConsumptionShort(hass, 1512.34567, "kWh"),
       "1.51 MWh"
@@ -105,23 +112,31 @@ describe("Energy Short Format Test", () => {
       formatConsumptionShort(hass, 15123456789.9, "kWh"),
       "15.1 TWh"
     );
-
     assert.strictEqual(
       formatConsumptionShort(hass, 15123456789000.9, "kWh"),
       "15,123 TWh"
     );
-
-    assert.strictEqual(formatConsumptionShort(hass, 1000.1, "GWh"), "1 TWh");
-
+  });
+  it("Downward Unit conversion", () => {
+    assert.strictEqual(formatConsumptionShort(hass, 0.00012, "kWh"), "0.12 Wh");
+    assert.strictEqual(formatConsumptionShort(hass, 0.12345, "kWh"), "123 Wh");
     assert.strictEqual(
-      formatConsumptionShort(hass, 10000.12345, "gal"),
-      "10,000 gal"
+      formatConsumptionShort(hass, 0.00001234, "TWh"),
+      "12.3 MWh"
+    );
+  });
+  it("Negativ Consumption", () => {
+    assert.strictEqual(
+      formatConsumptionShort(hass, -500.123, "kWh"),
+      "-500 kWh"
     );
-
-    // Don't really modify negative numbers, but make sure it's something sane.
     assert.strictEqual(
       formatConsumptionShort(hass, -1234.56, "kWh"),
-      "-1,234.56 kWh"
+      "-1.23 MWh"
+    );
+    assert.strictEqual(
+      formatConsumptionShort(hass, -0.001234, "kWh"),
+      "-1.23 Wh"
     );
   });
 });