diff --git a/xCAT-test/unit/blade_findme_chassis_filter.t b/xCAT-test/unit/blade_findme_chassis_filter.t
new file mode 100644
index 000000000..ed29eaa67
--- /dev/null
+++ b/xCAT-test/unit/blade_findme_chassis_filter.t
@@ -0,0 +1,101 @@
+#!/usr/bin/env perl
+use strict;
+use warnings;
+
+use FindBin;
+use File::Spec;
+use Test::More;
+
+my $plugin = File::Spec->catfile( $FindBin::Bin, '..', '..',
+    'xCAT-server', 'lib', 'xcat', 'plugins', 'blade.pm' );
+plan skip_all => 'blade.pm not found' unless -r $plugin;
+
+open( my $fh, '<', $plugin ) or die "Unable to read $plugin: $!";
+my $source = do { local $/; <$fh> };
+close($fh);
+
+# blade.pm needs a management node to load, so lift the routine out and drive
+# the real code on its own.
+my ($routine) = $source =~ /(sub blade_nodes_from_mp \{.*?\n\}\n)/s;
+BAIL_OUT('could not extract blade_nodes_from_mp from blade.pm') unless $routine;
+eval "package BladeFilter; $routine 1;" or BAIL_OUT("could not evaluate the routine: $@");
+
+sub blades { return [ sort( BladeFilter::blade_nodes_from_mp(@_) ) ]; }
+
+# xCAT::PPCdb::add_systemX writes a management module with its own name as the
+# mpa and no hardware type. The mp template in xCAT/templates/e1350 writes the
+# blades of that chassis with an mpa and a slot and no hardware type either,
+# so the chassis is what tells the two apart.
+my @chassis = (
+    { node => 'amm1',    mpa => 'amm1', id => '0' },
+    { node => 'blade01', mpa => 'amm1', id => '1' },
+    { node => 'blade14', mpa => 'amm1', id => '14' },
+);
+is_deeply( blades(@chassis), [ 'blade01', 'blade14' ],
+    'the blades of a chassis are asked and the chassis is not' );
+
+# A row that gives blade as its hardware type needs no chassis.
+is_deeply( blades( { node => 'x220a', nodetype => 'blade' } ), ['x220a'],
+    'a row that names its hardware type is asked' );
+is_deeply( blades( { node => 'x240a', nodetype => ' BLADE ' } ), ['x240a'],
+    'the hardware type is read whatever its case and spacing' );
+
+# lsslp writes the rest of this table. None of it answers a blade inventory.
+foreach my $type (qw(mm cmm pbmc fsp bpa hmc ivm cec frame lpar imm2)) {
+    is_deeply( blades( { node => "dev_$type", nodetype => $type } ), [],
+        "a $type is not asked for a blade inventory" );
+}
+
+# Hardware that gives a type of its own is left alone even when it names a
+# chassis, or a Power BMC that shares a rack with a chassis joins the inventory.
+is_deeply(
+    blades(
+        { node => 'cmm01',  mpa => 'cmm01', nodetype => 'cmm' },
+        { node => 'pbmc02', mpa => 'cmm01', nodetype => 'pbmc' },
+    ),
+    [],
+    'a Power BMC that names a chassis is still not asked'
+);
+
+# Only a management module owns blades. A row that hangs off another blade is
+# not a blade of a chassis.
+is_deeply(
+    blades(
+        { node => 'x220a', nodetype => 'blade' },
+        { node => 'weird', mpa => 'x220a' },
+    ),
+    ['x220a'],
+    'a row whose chassis is not a management module is not asked'
+);
+
+# A management module that lsslp wrote through its cmm branch names itself and
+# gives a hardware type.
+is_deeply(
+    blades(
+        { node => 'cmm01',   mpa => 'cmm01', nodetype => 'cmm' },
+        { node => 'bladeA',  mpa => 'cmm01', id => '1' },
+    ),
+    ['bladeA'],
+    'a chassis that gives its hardware type still owns its blades'
+);
+
+# Without the chassis there is nothing to reach the blade through.
+is_deeply( blades( { node => 'orphan', mpa => 'absentchassis' } ), [],
+    'a row whose chassis is not in the table is not asked' );
+is_deeply( blades( { node => 'lonely' } ), [],
+    'a row with no hardware type and no chassis is not asked' );
+
+# Defensive input from a table read.
+is_deeply( blades(), [], 'an empty table asks nothing' );
+is_deeply( blades( {}, { node => 'x220b', nodetype => 'blade' } ), ['x220b'],
+    'a row without a node name is skipped' );
+
+# The caller has to read the two attributes the routine needs, and has to stop
+# before the work that reads the arp table when nothing is left to ask.
+like( $source, qr/getAllNodeAttribs\(\[qw\(node nodetype mpa\)\]\)/,
+    'the findme request reads the hardware type and the chassis' );
+like( $source,
+    qr/my \@blades\s*=\s*blade_nodes_from_mp\(\@bladents\);.*?unless \(\@blades\) \{ return; \}/s,
+    'the handler returns when the table holds no blades' );
+
+done_testing();