fix: debounce slider to avoid laggy behavior (#18980)

resolves #18856 
resolves coder/internal#753

site/src/modules/workspaces/DynamicParameter/DynamicParameter.tsx

@@ -77,14 +77,14 @@ export const DynamicParameter: FC<DynamicParameterProps> = ({
 			/>
 			<div className="max-w-lg">
 				{parameter.form_type === "input" ||
-				parameter.form_type === "textarea" ? (
+				parameter.form_type === "textarea" ||
+				parameter.form_type === "slider" ? (
 					<DebouncedParameterField
 						id={id}
 						parameter={parameter}
 						value={value}
 						onChange={onChange}
 						disabled={disabled}
-						isPreset={isPreset}
 					/>
 				) : (
 					<ParameterField
@@ -250,7 +250,6 @@ interface DebouncedParameterFieldProps {
 	onChange: (value: string) => void;
 	disabled?: boolean;
 	id: string;
-	isPreset?: boolean;
 }
 
 const DebouncedParameterField: FC<DebouncedParameterFieldProps> = ({
@@ -259,7 +258,6 @@ const DebouncedParameterField: FC<DebouncedParameterFieldProps> = ({
 	onChange,
 	disabled,
 	id,
-	isPreset,
 }) => {
 	const [localValue, setLocalValue] = useState(
 		value !== undefined ? value : validValue(parameter.value),
@@ -271,13 +269,13 @@ const DebouncedParameterField: FC<DebouncedParameterFieldProps> = ({
 	const prevDebouncedValueRef = useRef<string | undefined>();
 	const prevValueRef = useRef(value);
 
-	// This is necessary in the case of fields being set by preset parameters
+	// Necessary for dynamic defaults or fields being set by preset parameters
 	useEffect(() => {
-		if (isPreset && value !== undefined && value !== prevValueRef.current) {
+		if (value !== undefined && value !== prevValueRef.current) {
 			setLocalValue(value);
 			prevValueRef.current = value;
 		}
-	}, [value, isPreset]);
+	}, [value]);
 
 	useEffect(() => {
 		// Only call onChangeEvent if debouncedLocalValue is different from the previously committed value
@@ -408,6 +406,31 @@ const DebouncedParameterField: FC<DebouncedParameterFieldProps> = ({
 				</Stack>
 			);
 		}
+
+		case "slider": {
+			const numericValue = Number.isFinite(Number(localValue))
+				? Number(localValue)
+				: 0;
+			const { validation_min: min = 0, validation_max: max = 100 } =
+				parameter.validations[0] ?? {};
+
+			return (
+				<div className="flex flex-row items-baseline gap-3">
+					<Slider
+						id={id}
+						className="mt-2"
+						value={[numericValue]}
+						onValueChange={([value]) => {
+							setLocalValue(value.toString());
+						}}
+						min={min ?? undefined}
+						max={max ?? undefined}
+						disabled={disabled}
+					/>
+					<span className="w-4 font-medium">{numericValue}</span>
+				</div>
+			);
+		}
 	}
 };
 
@@ -564,25 +587,6 @@ const ParameterField: FC<ParameterFieldProps> = ({
 				</div>
 			);
 
-		case "slider":
-			return (
-				<div className="flex flex-row items-baseline gap-3">
-					<Slider
-						id={id}
-						className="mt-2"
-						value={[Number.isFinite(Number(value)) ? Number(value) : 0]}
-						onValueChange={([value]) => {
-							onChange(value.toString());
-						}}
-						min={parameter.validations[0]?.validation_min ?? 0}
-						max={parameter.validations[0]?.validation_max ?? 100}
-						disabled={disabled}
-					/>
-					<span className="w-4 font-medium">
-						{Number.isFinite(Number(value)) ? value : "0"}
-					</span>
-				</div>
-			);
 		case "error":
 			return <Diagnostics diagnostics={parameter.diagnostics} />;
 	}