Qute: if section - adjust the evaluation rules for equality operators

- fixes quarkusio#44610

docs/src/main/asciidoc/qute-reference.adoc

@@ -774,11 +774,11 @@ A loop section may also define the `{#else}` block that is executed when there a
 [[if_section]]
 ==== If Section
 
-The `if` section represents a basic control flow section.
+The `{#if}` section represents a basic control flow section.
 The simplest possible version accepts a single parameter and renders the content if the condition is evaluated to `true`.
 A condition without an operator evaluates to `true` if the value is not considered `falsy`, i.e. if the value is not `null`, `false`, an empty collection, an empty map, an empty array, an empty string/char sequence or a number equal to zero.
 
-[source]
+[source,html]
 ----
 {#if item.active}
   This item is active.
@@ -788,68 +788,94 @@ A condition without an operator evaluates to `true` if the value is not consider
 You can also use the following operators in a condition:
 
 |===
-|Operator |Aliases |Precedence (higher wins)
+|Operator |Aliases |Precedence |Example | Description
 
 |logical complement
 |`!`
-| 4
+|4
+|`{#if !item.active}{/if}`
+|Inverts the evaluated value.
 
 |greater than
 |`gt`, `>`
-| 3
+|3
+|`{#if item.age > 43}This item is very old.{/if}`
+|Evaluates to `true` if `value1` is greater than `value2`.
 
 |greater than or equal to
 |`ge`, `>=`
 | 3
+|`{#if item.price >= 100}This item is expensive.{/if}`
+|Evaluates to `true` if `value1` is greater than or equal to `value2`.
 
 |less than
 |`lt`, `<`
 | 3
+|`{#if item.price < 100}This item is cheap.{/if}`
+|Evaluates to `true` if `value1` is less than `value2`.
 
 |less than or equal to
 |`le`, `\<=`
 | 3
+|`{#if item.age <= 43}This item is young.{/if}`
+|Evaluates to `true` if `value1` is less than or equal to `value2`.
 
 |equals
 |`eq`, `==`, `is`
 | 2
+|`{#if item.name eq 'Foo'}Foo item!{/if}`
+|Evaluates to `true` if `value1` is equal to `value2`.
 
 |not equals
 |`ne`, `!=`
 | 2
+|`{#if item.name != 'Bar'}Not a Bar item!{/if}`
+|Evaluates to `true` if `value1` is not equal to `value2`.
 
 |logical AND (short-circuiting)
 |`&&`, `and`
 | 1
+|`{#if item.price > 100 && item.isActive}Expensive and active item.{/if}`
+|Evaluates to `true` if both operands evaluate to `true`.
 
 |logical OR (short-circuiting)
 |`\|\|`, `or`
 | 1
+|`{#if item.price > 100 \|\| item.isActive}Expensive or active item.{/if}`
+|Evaluates to `true` if one of the operands evaluates to `true`.
 
 |===
 
-.A simple operator example
-[source]
-----
-{#if item.age > 10}
-  This item is very old.
-{/if}
-----
+For `>`, `>=`, `<`, and `\<=` the following rules are applied:
+
+* Neither of the operands may be `null`.
+* If both operands are of the same type that implements the `java.lang.Comparable` then the `Comparable#compareTo(T)` method is used to perform comparison.
+* Otherwise, both operands are coerced to `java.math.BigDecimal` first and then the `BigDecimal#compareTo(BigDecimal)` method is used to perform comparison.
+
+NOTE: Types that support coercion include `BigInteger`, `Integer`, `Long`, `Double`, `Float` and `String`.
+
+For `==` and `!=` the following rules are applied:
+
+* Identical objects are considered equal.
+* If at least one object is an instance of `java.lang.Number` then:
+** If both operands are of the same type then `java.lang.Object#equals(Object)` is used.
+** Otherwise, both operands are coerced to `java.math.BigDecimal` first and then the `BigDecimal#compareTo(BigDecimal)` method is used to perform comparison.
+* Otherwise, `java.util.Objects#equals(Object, Object)` is used to compare the arguments.
 
 Multiple conditions are also supported.
 
 .Multiple conditions example
-[source]
+[source,html]
 ----
 {#if item.age > 10 && item.price > 500}
   This item is very old and expensive.
 {/if}
 ----
 
-Precedence rules can be overridden by parentheses.
+The default precedence rules (higher precedence wins) can be overridden by parentheses.
 
 .Parentheses example
-[source]
+[source,html]
 ----
 {#if (item.age > 10 || item.price > 500) && user.loggedIn}
   User must be logged in and item age must be > 10 or price must be > 500.
@@ -859,7 +885,7 @@ Precedence rules can be overridden by parentheses.
 
 You can also add any number of `else` blocks:
 
-[source]
+[source,html]
 ----
 {#if item.age > 10}
   This item is very old.

independent-projects/qute/core/src/main/java/io/quarkus/qute/IfSectionHelper.java

@@ -476,9 +476,9 @@ int getPrecedence() {
         boolean evaluate(Object op1, Object op2) {
             switch (this) {
                 case EQ:
-                    return Objects.equals(op1, op2);
+                    return equals(op1, op2);
                 case NE:
-                    return !Objects.equals(op1, op2);
+                    return !equals(op1, op2);
                 case GE:
                 case GT:
                 case LE:
@@ -492,6 +492,21 @@ boolean evaluate(Object op1, Object op2) {
             }
         }
 
+        boolean equals(Object op1, Object op2) {
+            if (op1 == op2) {
+                return true;
+            }
+            if (op1 != null && op2 != null && (op1 instanceof Number || op2 instanceof Number)) {
+                if (op1.getClass().equals(op2.getClass())) {
+                    // Both operands are of the same Number type
+                    return op1.equals(op2);
+                }
+                // Both operands are not null and at least one of them is a number
+                return getDecimal(op1).compareTo(getDecimal(op2)) == 0;
+            }
+            return Objects.equals(op1, op2);
+        }
+
         @SuppressWarnings({ "rawtypes", "unchecked" })
         boolean compare(Object op1, Object op2) {
             if (op1 == null || op2 == null) {
@@ -553,25 +568,22 @@ static Operator from(String value) {
         }
 
         static BigDecimal getDecimal(Object value) {
-            BigDecimal decimal;
-            if (value instanceof BigDecimal) {
-                decimal = (BigDecimal) value;
-            } else if (value instanceof BigInteger) {
-                decimal = new BigDecimal((BigInteger) value);
-            } else if (value instanceof Integer) {
-                decimal = new BigDecimal((Integer) value);
-            } else if (value instanceof Long) {
-                decimal = new BigDecimal((Long) value);
-            } else if (value instanceof Double) {
-                decimal = new BigDecimal((Double) value);
-            } else if (value instanceof Float) {
-                decimal = new BigDecimal((Float) value);
-            } else if (value instanceof String) {
-                decimal = new BigDecimal(value.toString());
-            } else {
-                throw new TemplateException("Not a valid number: " + value);
-            }
-            return decimal;
+            if (value instanceof BigDecimal decimal) {
+                return decimal;
+            } else if (value instanceof BigInteger bigInteger) {
+                return new BigDecimal(bigInteger);
+            } else if (value instanceof Integer integer) {
+                return new BigDecimal(integer);
+            } else if (value instanceof Long _long) {
+                return new BigDecimal(_long);
+            } else if (value instanceof Double _double) {
+                return new BigDecimal(_double);
+            } else if (value instanceof Float _float) {
+                return new BigDecimal(_float);
+            } else if (value instanceof String string) {
+                return new BigDecimal(string);
+            }
+            throw new TemplateException("Cannot coerce " + value + " to a BigDecimal");
         }
 
     }

independent-projects/qute/core/src/test/java/io/quarkus/qute/IfSectionTest.java

@@ -262,6 +262,19 @@ public void testParameterOrigin() {
         }
     }
 
+    @Test
+    public void testComparisons() {
+        Engine engine = Engine.builder().addDefaults().build();
+        assertEquals("longGtInt", engine.parse("{#if val > 10}longGtInt{/if}").data("val", 11l).render());
+        assertEquals("doubleGtInt", engine.parse("{#if val > 10}doubleGtInt{/if}").data("val", 20.0).render());
+        assertEquals("longGtStr", engine.parse("{#if val > '10'}longGtStr{/if}").data("val", 11l).render());
+        assertEquals("longLeStr", engine.parse("{#if val <= '10'}longLeStr{/if}").data("val", 1l).render());
+        assertEquals("longEqInt", engine.parse("{#if val == 10}longEqInt{/if}").data("val", 10l).render());
+        assertEquals("doubleEqInt", engine.parse("{#if val == 10}doubleEqInt{/if}").data("val", 10.0).render());
+        assertEquals("doubleEqFloat", engine.parse("{#if val == 10.00f}doubleEqFloat{/if}").data("val", 10.0).render());
+        assertEquals("longEqLong", engine.parse("{#if val eq 10l}longEqLong{/if}").data("val", Long.valueOf(10)).render());
+    }
+
     public static class Target {
 
         public ContentStatus status;