diff --git a/hledger/test/journal/directive-commodity.test b/hledger/test/journal/directive-commodity.test
index 35ea6833a..24d970636 100644
--- a/hledger/test/journal/directive-commodity.test
+++ b/hledger/test/journal/directive-commodity.test
@@ -1,13 +1,73 @@
 # commodity directive
-<
-commodity BTC
-$ hledger -f - reg
 
-# commodity directive with subdirective
+# 1 requires an argument
 <
-commodity BTC
-  note Bitcoin
-$ hledger -f - reg
->2 /expecting "format"/
+commodity
+$ hledger -f - commodities
+>2 /unexpected newline/
 >=1
 
+# 2 should require an amount, not just a symbol (but doesn't, TODO)
+<
+commodity A
+$ hledger -f - commodities
+A
+
+# 3 when there is an amount, a decimal mark is required
+<
+commodity A 1
+$ hledger -f - commodities
+>2 /Please include a decimal point or decimal comma/
+>=1
+
+# 4
+<
+commodity A 1.
+$ hledger -f - commodities
+A
+
+# 5
+<
+commodity A 1,00
+$ hledger -f - commodities
+A
+
+# 6 accepts a format subdirective
+<
+commodity A
+  format 1.0 A
+$ hledger -f - commodities
+A
+
+# 7 which also requires an amount argument
+<
+commodity A
+  format 
+$ hledger -f - commodities
+>2 /expecting amount/
+>=1
+
+# 8 which must have the same commodity symbol
+<
+commodity A
+  format 1
+$ hledger -f - commodities
+>2 /commodity directive symbol .* and format directive symbol .* should be the same/
+>=1
+
+# 9 when there's a format subdirective, the main directive should have just a symbol
+# (and the error message should be clear, TODO)
+<
+commodity A 1.
+  format 1. A
+$ hledger -f - commodities
+>2 /unexpected 'f'/
+>=1
+
+# 10 it rejects unrecognised subdirectives (should be permissive like account, TODO)
+<
+commodity A
+  note a a
+$ hledger -f - commodities
+>2 /expecting "format"/
+>=1