patch 7.4.1663
Problem:    In tests it's often useful to check if a pattern matches.
Solution:   Add assert_match().
diff --git a/src/testdir/test_assert.vim b/src/testdir/test_assert.vim
index 2ac828b..bc025b4 100644
--- a/src/testdir/test_assert.vim
+++ b/src/testdir/test_assert.vim
@@ -57,14 +57,26 @@
     call assert_equal(s:w, '')
   catch
     call assert_exception('E724:')
-    call assert_true(v:errors[0] =~ "Expected NULL but got ''")
+    call assert_match("Expected NULL but got ''", v:errors[0])
     call remove(v:errors, 0)
   endtry
 endfunc
 
+func Test_match()
+  call assert_match('^f.*b.*r$', 'foobar')
+
+  call assert_match('bar.*foo', 'foobar')
+  call assert_match("Pattern 'bar.*foo' does not match 'foobar'", v:errors[0])
+  call remove(v:errors, 0)
+
+  call assert_match('bar.*foo', 'foobar', 'wrong')
+  call assert_match('wrong', v:errors[0])
+  call remove(v:errors, 0)
+endfunc
+
 func Test_assert_fail_fails()
   call assert_fails('xxx', {})
-  call assert_true(v:errors[0] =~ "Expected {} but got 'E731:")
+  call assert_match("Expected {} but got 'E731:", v:errors[0])
   call remove(v:errors, 0)
 endfunc
 
diff --git a/src/testdir/test_channel.vim b/src/testdir/test_channel.vim
index 7051223..94311e9 100644
--- a/src/testdir/test_channel.vim
+++ b/src/testdir/test_channel.vim
@@ -154,7 +154,7 @@
   " Request command "foo bar", which fails silently.
   call assert_equal('ok', ch_evalexpr(handle, 'bad command'))
   call s:waitFor('v:errmsg =~ "E492"')
-  call assert_true(v:errmsg =~ 'E492:.*foo bar')
+  call assert_match('E492:.*foo bar', v:errmsg)
 
   call assert_equal('ok', ch_evalexpr(handle, 'do normal', {'timeout': 100}))
   call s:waitFor('"added more" == getline("$")')