Added `be' support as an expectation handler

E.g. "to be silent".

src/expect-core

@@ -56,6 +56,14 @@ __chk-nshift()
 }
 
 
+##
+# Purely gramatical to make certain expectations flow more naturally when
+# spoken
+#
+# For example, "to be silent".
+_expect--be() { _proxy-to "$@"; }
+
+
 _expect--succeed() { test "$1" -eq 0; }
 _expect--fail()    { test "$1" -ne 0; }
 

src/spec

@@ -32,6 +32,9 @@ __INC_SPEC=1
 source specstack
 source expect-core
 
+# number of internal arguments before remainder clause
+declare -ir __SHIFTN=3
+
 
 ##
 # Attempts to make tempoary path in /dev/shm, falling back to default
@@ -156,13 +159,24 @@ to()
 
   [ $# -gt 0 ] || _bail "missing assertion string for \`to'" $__spec_caller
 
-  local -r expect_full="$*"
-  local -r type="$1"
-  shift
-
   _sstack-assert-follow :expect to $(caller)
   _sstack-pop
 
+  _handle-to "$@" || fail "$*"
+
+  __spec_caller=
+}
+
+
+##
+# Perform expectation assertion by invoking expectation handler
+#
+# Will throw an error if the handler cannot be found.
+_handle-to()
+{
+  local -r type="$1"
+  shift
+
   local -r assert="_expect--$type"
   type "$assert" &>/dev/null \
     || _bail "unknown expectation: \`$type'" $__spec_caller
@@ -172,10 +186,22 @@ to()
   # output file, and all remaining arguments are said remainder clause; the
   # shift argument allows the implementation to vary without breaking BC so
   # long as the meaning of the shifted arguments do not change
-  $assert "$__spec_rexit" 3 "$__spec_errpath" "$@" <<< "$__spec_result" \
+  $assert "$__spec_rexit" $__SHIFTN "$__spec_errpath" "$@" \
-    || fail "$expect_full"
+      <<< "$__spec_result"
+}
 
-  __spec_caller=
+
+##
+# Proxies remainder clause to an expectation handler
+#
+# This is different than simply invoking `_handle-to` in that the former
+# expects to be called with arguments from an existing handler call (that
+# is, in need of shifting to access the remainder clause), where as the
+# latter assumes that its arguments are *only* the intended remainder clause
+_proxy-to()
+{
+  shift $__SHIFTN
+  _handle-to "$@"
 }
 
 

test/test-spec

@@ -291,5 +291,34 @@ describe expect
       '; to succeed
     end
   end
+
+
+  describe be
+    it cannot stand alone
+      expect test-run <<< '
+        describe foo
+          it should fail
+            expect true
+              to be
+          end
+        end
+      '; to fail
+    end
+
+    it processes arguments as if it did not exist
+      expect test-run <<< '
+        expected="foo bar baz"
+        _expect--awesome() { shift "$2"; test "$*" == "$expected"; }
+
+        describe foo
+          it should succeed
+            expect true
+              # ignore the fact that this sounds awkward
+              to be awesome $expected
+          end
+        end
+      '; to succeed
+    end
+  end
 end