armory/Sources/armory/system/Assert.hx
2021-09-12 00:03:57 +02:00

132 lines
3.9 KiB
Haxe

package armory.system;
import haxe.Exception;
import haxe.PosInfos;
import haxe.exceptions.PosException;
import haxe.macro.Context;
import haxe.macro.Expr;
using haxe.macro.ExprTools;
class Assert {
/**
Checks whether the given expression evaluates to true. If this is not
the case, an `ArmAssertionException` is thrown or a warning is printed
(depending on the assertion level).
The assert level describes the severity of the assertion. If the
severity is lower than the level stored in the `arm_assert_level` flag,
the assertion is omitted from the code so that it doesn't decrease the
runtime performance.
@param level The severity of this assertion.
@param condition The conditional expression to test.
@param message Optional message to display when the assertion fails.
@see `AssertLevel`
**/
macro public static function assert(level: ExprOf<AssertLevel>, condition: ExprOf<Bool>, ?message: ExprOf<String>): Expr {
final levelVal: AssertLevel = AssertLevel.fromExpr(level);
final assertThreshold = AssertLevel.fromString(Context.definedValue("arm_assert_level"));
if (levelVal < assertThreshold) {
return macro {};
}
switch (levelVal) {
case Warning:
return macro {
if (!$condition) {
@:pos(condition.pos)
trace(@:privateAccess armory.system.Assert.ArmAssertionException.formatMessage($v{condition.toString()}, ${message}));
}
}
case Error:
return macro {
if (!$condition) {
#if arm_assert_quit kha.System.stop(); #end
@:pos(condition.pos)
@:privateAccess armory.system.Assert.throwAssertionError($v{condition.toString()}, ${message});
}
}
default:
throw new Exception('Unsupported assert level: $levelVal');
}
}
/**
Helper function to prevent Haxe "bug" that actually throws an error
even when using `macro throw` (inlining this method also does not work).
**/
static function throwAssertionError(exprString: String, message: String, ?pos: PosInfos) {
throw new ArmAssertionException(exprString, message, pos);
}
}
/**
Exception that is thrown when an assertion fails.
@see `Assert`
**/
class ArmAssertionException extends PosException {
/**
@param exprString The string representation of the failed assert condition.
@param message Custom error message, use `null` to omit this.
**/
public inline function new(exprString: String, message: Null<String>, ?previous: Exception, ?pos: Null<PosInfos>) {
super('\n${formatMessage(exprString, message)}', previous, pos);
}
static inline function formatMessage(exprString: String, message: Null<String>): String {
final optMsg = message != null ? '\n\tMessage: $message' : "";
return 'Failed assertion:$optMsg\n\tExpression: ($exprString)';
}
}
enum abstract AssertLevel(Int) from Int to Int {
/**
Assertions with this severity don't throw exceptions and only print to
the console.
**/
var Warning: AssertLevel = 0;
/**
Assertions with this severity throw an `ArmAssertionException` if they
fail, and optionally quit the game if the `arm_assert_quit` flag is set.
**/
var Error: AssertLevel = 1;
/**
Completely disable assertions. Don't use this level in `assert()` calls!
**/
var NoAssertions: AssertLevel = 2;
public static function fromExpr(e: ExprOf<AssertLevel>): AssertLevel {
switch (e.expr) {
case EConst(CIdent(v)): return fromString(v);
default: throw new Exception('Unsupported expression: $e');
};
}
/**
Converts a string into an `AssertLevel`, the string must be spelled
exactly as the assert level. `null` defaults to
`AssertLevel.NoAssertions`.
**/
public static function fromString(s: Null<String>): AssertLevel {
return switch (s) {
case "Warning": Warning;
case "Error": Error;
case "NoAssertions" | null: NoAssertions;
default: throw new Exception('Could not convert "$s" to AssertLevel');
}
}
@:op(A < B) static function lt(a: AssertLevel, b: AssertLevel): Bool;
@:op(A > B) static function gt(a: AssertLevel, b: AssertLevel): Bool;
}