From f1e530ac397ece0b21e443a876309eed586fc65f Mon Sep 17 00:00:00 2001
From: Rangi <35663410+Rangi42@users.noreply.github.com>
Date: Sat, 26 Sep 2026 13:55:35 -0400
Subject: [PATCH] Make the comma after `assert warn/fail/fatal` optional
 (#2160)

Co-authored-by: Eldred Habert <me@eldred.fr>
---
 man/rgbasm.5              | 15 ++++++++++----
 src/asm/parser.y          |  6 +++---
 test/asm/assert-comma.asm | 24 ++++++++++++++++++++++
 test/asm/assert-comma.err | 42 +++++++++++++++++++++++++++++++++++++++
 test/asm/assert-comma.out | 21 ++++++++++++++++++++
 5 files changed, 101 insertions(+), 7 deletions(-)
 create mode 100644 test/asm/assert-comma.asm
 create mode 100644 test/asm/assert-comma.err
 create mode 100644 test/asm/assert-comma.out

diff --git a/man/rgbasm.5 b/man/rgbasm.5
index c601953b..d4531a38 100644
--- a/man/rgbasm.5
+++ b/man/rgbasm.5
@@ -2529,16 +2529,16 @@ assert FirstByte + 1 == SecondByte
     STATIC_ASSERT .end - Function < 256, "Function is too large!"
 .Ed
 .Pp
-First, the difference between
+An
 .Ic ASSERT
-and
+is evaluated by RGBASM if it can, otherwise by RGBLINK; but a
 .Ic STATIC_ASSERT
-is that the former is evaluated by RGBASM if it can, otherwise by RGBLINK; but the latter is only ever evaluated by RGBASM.
+that RGBASM cannot evaluate will raise an error.
 If RGBASM cannot compute the value of the argument to
 .Ic STATIC_ASSERT ,
 it will produce an error.
 .Pp
-Second, as shown above, a string can be optionally added at the end, to give insight into what the assertion is checking.
+As shown above, a message string can be optionally added as the last argument, to give insight into what the assertion is checking.
 .Pp
 Finally, you can add one of
 .Ic WARN , FAIL
@@ -2559,6 +2559,13 @@ to be emitted;
 (the default) will cause a non-fatal error; and
 .Ic FATAL
 immediately aborts.
+The comma after this argument is optional; so for example,
+.Ql ASSERT WARN n == 2 ,
+.Ql ASSERT WARN, n == 2 ,
+.Ql ASSERT WARN n == 2, "n != 2" ,
+and
+.Ql ASSERT WARN, n == 2, "n != 2"
+are all valid.
 .Sh MISCELLANEOUS
 .Ss Changing options while assembling
 .Ic OPT
diff --git a/src/asm/parser.y b/src/asm/parser.y
index 44a55d80..16fbe9c2 100644
--- a/src/asm/parser.y
+++ b/src/asm/parser.y
@@ -752,13 +752,13 @@ assert_type:
 	%empty {
 		$$ = ASSERT_ERROR;
 	}
-	| POP_WARN COMMA {
+	| POP_WARN trailing_comma {
 		$$ = ASSERT_WARN;
 	}
-	| POP_FAIL COMMA {
+	| POP_FAIL trailing_comma {
 		$$ = ASSERT_ERROR;
 	}
-	| POP_FATAL COMMA {
+	| POP_FATAL trailing_comma {
 		$$ = ASSERT_FATAL;
 	}
 ;
diff --git a/test/asm/assert-comma.asm b/test/asm/assert-comma.asm
new file mode 100644
index 00000000..4b1756dc
--- /dev/null
+++ b/test/asm/assert-comma.asm
@@ -0,0 +1,24 @@
+def n = 0
+for i_type, 5
+	redef type equs strslice("     warn fail warn,fail,", i_type * 5, (i_type + 1) * 5)
+	for i_message, 2
+		redef message equs ", \"hello {d:n}\""
+		redef message equs strslice(#message, 0, i_message * strlen(#message))
+		for cond, 2
+			redef line equs "assert {type} {cond} {message}"
+			println "[static_]{line}"
+			{line}
+			static_{line}
+			def n += 1
+		endr
+	endr
+endr
+
+println "[static_]assert fatal..."
+assert fatal 1
+assert fatal 1, "goodbye 0"
+static_assert fatal 1
+static_assert fatal 1, "goodbye 0"
+
+assert fatal 0
+assert fatal 0, "goodbye 1" ; not reached
diff --git a/test/asm/assert-comma.err b/test/asm/assert-comma.err
new file mode 100644
index 00000000..f40ab3e7
--- /dev/null
+++ b/test/asm/assert-comma.err
@@ -0,0 +1,42 @@
+error: Assertion failed
+    at assert-comma.asm::REPT~1::REPT~1::REPT~1(10) <- assert-comma.asm::REPT~1::REPT~1(7) <- assert-comma.asm::REPT~1(4) <- assert-comma.asm(2)
+error: Assertion failed
+    at assert-comma.asm::REPT~1::REPT~1::REPT~1(11) <- assert-comma.asm::REPT~1::REPT~1(7) <- assert-comma.asm::REPT~1(4) <- assert-comma.asm(2)
+error: Assertion failed: hello 2
+    at assert-comma.asm::REPT~1::REPT~2::REPT~1(10) <- assert-comma.asm::REPT~1::REPT~2(7) <- assert-comma.asm::REPT~1(4) <- assert-comma.asm(2)
+error: Assertion failed: hello 2
+    at assert-comma.asm::REPT~1::REPT~2::REPT~1(11) <- assert-comma.asm::REPT~1::REPT~2(7) <- assert-comma.asm::REPT~1(4) <- assert-comma.asm(2)
+warning: Assertion failed [-Wassert]
+    at assert-comma.asm::REPT~2::REPT~1::REPT~1(10) <- assert-comma.asm::REPT~2::REPT~1(7) <- assert-comma.asm::REPT~2(4) <- assert-comma.asm(2)
+warning: Assertion failed [-Wassert]
+    at assert-comma.asm::REPT~2::REPT~1::REPT~1(11) <- assert-comma.asm::REPT~2::REPT~1(7) <- assert-comma.asm::REPT~2(4) <- assert-comma.asm(2)
+warning: Assertion failed: hello 6 [-Wassert]
+    at assert-comma.asm::REPT~2::REPT~2::REPT~1(10) <- assert-comma.asm::REPT~2::REPT~2(7) <- assert-comma.asm::REPT~2(4) <- assert-comma.asm(2)
+warning: Assertion failed: hello 6 [-Wassert]
+    at assert-comma.asm::REPT~2::REPT~2::REPT~1(11) <- assert-comma.asm::REPT~2::REPT~2(7) <- assert-comma.asm::REPT~2(4) <- assert-comma.asm(2)
+error: Assertion failed
+    at assert-comma.asm::REPT~3::REPT~1::REPT~1(10) <- assert-comma.asm::REPT~3::REPT~1(7) <- assert-comma.asm::REPT~3(4) <- assert-comma.asm(2)
+error: Assertion failed
+    at assert-comma.asm::REPT~3::REPT~1::REPT~1(11) <- assert-comma.asm::REPT~3::REPT~1(7) <- assert-comma.asm::REPT~3(4) <- assert-comma.asm(2)
+error: Assertion failed: hello 10
+    at assert-comma.asm::REPT~3::REPT~2::REPT~1(10) <- assert-comma.asm::REPT~3::REPT~2(7) <- assert-comma.asm::REPT~3(4) <- assert-comma.asm(2)
+error: Assertion failed: hello 10
+    at assert-comma.asm::REPT~3::REPT~2::REPT~1(11) <- assert-comma.asm::REPT~3::REPT~2(7) <- assert-comma.asm::REPT~3(4) <- assert-comma.asm(2)
+warning: Assertion failed [-Wassert]
+    at assert-comma.asm::REPT~4::REPT~1::REPT~1(10) <- assert-comma.asm::REPT~4::REPT~1(7) <- assert-comma.asm::REPT~4(4) <- assert-comma.asm(2)
+warning: Assertion failed [-Wassert]
+    at assert-comma.asm::REPT~4::REPT~1::REPT~1(11) <- assert-comma.asm::REPT~4::REPT~1(7) <- assert-comma.asm::REPT~4(4) <- assert-comma.asm(2)
+warning: Assertion failed: hello 14 [-Wassert]
+    at assert-comma.asm::REPT~4::REPT~2::REPT~1(10) <- assert-comma.asm::REPT~4::REPT~2(7) <- assert-comma.asm::REPT~4(4) <- assert-comma.asm(2)
+warning: Assertion failed: hello 14 [-Wassert]
+    at assert-comma.asm::REPT~4::REPT~2::REPT~1(11) <- assert-comma.asm::REPT~4::REPT~2(7) <- assert-comma.asm::REPT~4(4) <- assert-comma.asm(2)
+error: Assertion failed
+    at assert-comma.asm::REPT~5::REPT~1::REPT~1(10) <- assert-comma.asm::REPT~5::REPT~1(7) <- assert-comma.asm::REPT~5(4) <- assert-comma.asm(2)
+error: Assertion failed
+    at assert-comma.asm::REPT~5::REPT~1::REPT~1(11) <- assert-comma.asm::REPT~5::REPT~1(7) <- assert-comma.asm::REPT~5(4) <- assert-comma.asm(2)
+error: Assertion failed: hello 18
+    at assert-comma.asm::REPT~5::REPT~2::REPT~1(10) <- assert-comma.asm::REPT~5::REPT~2(7) <- assert-comma.asm::REPT~5(4) <- assert-comma.asm(2)
+error: Assertion failed: hello 18
+    at assert-comma.asm::REPT~5::REPT~2::REPT~1(11) <- assert-comma.asm::REPT~5::REPT~2(7) <- assert-comma.asm::REPT~5(4) <- assert-comma.asm(2)
+FATAL: Assertion failed
+    at assert-comma.asm(23)
diff --git a/test/asm/assert-comma.out b/test/asm/assert-comma.out
new file mode 100644
index 00000000..7ee8d137
--- /dev/null
+++ b/test/asm/assert-comma.out
@@ -0,0 +1,21 @@
+[static_]assert       $0 
+[static_]assert       $1 
+[static_]assert       $0 , "hello 2"
+[static_]assert       $1 , "hello 2"
+[static_]assert warn  $0 
+[static_]assert warn  $1 
+[static_]assert warn  $0 , "hello 6"
+[static_]assert warn  $1 , "hello 6"
+[static_]assert fail  $0 
+[static_]assert fail  $1 
+[static_]assert fail  $0 , "hello 10"
+[static_]assert fail  $1 , "hello 10"
+[static_]assert warn, $0 
+[static_]assert warn, $1 
+[static_]assert warn, $0 , "hello 14"
+[static_]assert warn, $1 , "hello 14"
+[static_]assert fail, $0 
+[static_]assert fail, $1 
+[static_]assert fail, $0 , "hello 18"
+[static_]assert fail, $1 , "hello 18"
+[static_]assert fatal...