+# Environment access
+
+${env {USER}}
+${env {NO_SUCH_VARIABLE} {oops, success} {correct}}
+
+# JSON
+
+${extract json {Url} \
+ { \{ \"Url\": \"http://www.example.com/image/481989943\",\
+ \"Height\": 125,\
+ \"Width\": 100\
+ \} \
+ } \
+ }
+${extract json {Width} \
+ { \{ \"Url\": \"http://www.example.com/image/481989943\",\
+ \"Height\": 125,\
+ \"Width\": 100\
+ \} \
+ } \
+ }
+${extract json {2} {[116, 943, 234, 38793]} }
+${extract json {2} {${extract json{IDs} {\{"other":"foo", "IDs": [116, 943, 234]\} }}} }
+
+${extract json {2} {["red", "green", "blue", "black"]} }
+${extract jsons{2} {["red", "green", "blue", "black"]} }
+<${extract jsons{5} {["red", "green", "blue", "black"]} }>
+expect: <>
+
+${extract json {seconds} { \{"hours":0, "mins":0, "seconds":59\} }}
+${extract json {seconds} {${extract json {2} { ["irrelevant", \{"hours":0, "mins":0, "seconds":59\}] }}}}
+
+${extract json{IDs}{ \{"IDs": \{"1":116, "2":943, "3":234\}\} }}
+expect: {"1":116, "2":943, "3":234}
+
+${extract json{IDs}{ \{"id": \{"a":101, "b":102\}, "IDs": \{"1":116, "2":943, "3":234\}\} }}
+expect: {"1":116, "2":943, "3":234}
+
+<${extract json{nonexistent}{ \{"id": \{"a":101, "b":102\}, "IDs": \{"1":116, "2":943, "3":234\}\} }}>
+expect: <>
+<${extract jsons{nonexistent}{ \{"id": \{"a":101, "b":102\}, "IDs": \{"1":116, "2":943, "3":234\}\} }}>
+expect: <>
+
+# string value with embedded comma
+<${extract jsons{name}{ \{ "id":"1","name":"Doe, John","age":"unknown" \}}}>
+expect <Doe, John>
+# string value with embedded doublequote
+<${extract jsons{name}{ \{ "id":"1","name":"word1 \\\" word2","age":"unknown" \}}}>
+expect <word1 \\\" word2>
+
+${if forany_json {[1, 2, 3]}{={$item}{1}}{yes}{no}}
+${if forany_jsons{["A", "B", "C"]}{eq{$item}{B}}{yes}{no}}
+