Jackson 3: unguarded textValue()/asBoolean() throw where Jackson 2 returned defaults (JoinFunction, BooleanUtils) #434

Summary

Two unguarded coercion call sites changed behavior under the Jackson 3 migration (#430, PR #431). Jackson 3 tightened textValue() (now stringValue(), throws for any non‑String node) and the no‑arg asBoolean() (throws for non‑coercible node types). Jackson 2 returned null / false respectively. These lines were not changed by the migration, so behavior flipped from "return default" to "throw tools.jackson.databind.node.JsonNodeException".

Not caught by the test suite.

Where & reproductions

1. JoinFunction.java:121 — textValue() on non‑string inner element

} else if (element.isArray()) {
    for (Iterator<JsonNode> it = ((ArrayNode) element).iterator(); it.hasNext();) {
        stringJoiner.add(it.next().textValue());   // <-- no isTextual() guard
    }
}

Note the outer element at line 117 is guarded (element.isTextual()), but the inner loop at 121 is not.

• Repro: $join([[1, 2]])
• Jackson 2: textValue() returns null → StringJoiner appends "null" → result "nullnull".
• Jackson 3: throws JsonNodeException.

2. BooleanUtils.java:89 — asBoolean() on a BinaryNode

case BINARY:
    return node.asBoolean();

• Jackson 2: returns the default false for a BinaryNode.
• Jackson 3: throws JsonNodeException.
• Lower reachability (requires a BinaryNode reaching $boolean(...)), but it is an unguarded no‑arg coercion of exactly the kind this migration must audit.

Verified empirically against jackson‑databind 3.2.0

IntNode(5).textValue()    -> THROWS JsonNodeException
BinaryNode.asBoolean()    -> THROWS JsonNodeException

Related minor note (low priority)

ArrayUtils.compare (line 105, changed in this PR) now uses asText(""). For a container node this correctly restores the Jackson‑2 "", but for a POJONode it returns "" where Jackson 2 returned the POJO's toString(). Reachability is very low ($sort over a regex POJONode is not a realistic user path), so this is noted rather than treated as a separate defect.

Suggested fix

Add an isTextual() guard at JoinFunction:121 (matching line 117) — decide whether a non‑string inner element should stringify via the JSONata number/string rules or raise the existing ERR_MSG_ARG1_ARR_STR. For BooleanUtils:89, return false explicitly for the BINARY case rather than delegating to the now‑throwing asBoolean().