Merge pull request #4821 from jamessan/vim-7.4.1096

vim-patch:7.4.1096,7.4.1567

runtime/doc/eval.txt

@@ -1789,6 +1789,7 @@ argv({nr})			String	{nr} entry of the argument list
 argv()				List	the argument list
 assert_equal({exp}, {act} [, {msg}]) none  assert {exp} equals {act}
 assert_exception({error} [, {msg}])   none  assert {error} is in v:exception
+assert_fails( {cmd} [, {error}])      none  assert {cmd} fails
 assert_false({actual} [, {msg}])     none  assert {actual} is false
 assert_true({actual} [, {msg}])      none  assert {actual} is true
 asin({expr})			Float	arc sine of {expr}
@@ -2263,6 +2264,11 @@ assert_exception({error} [, {msg}])			*assert_exception()*
 			  call assert_exception('E492:')
 			endtry
 
+assert_fails({cmd} [, {error}])					*assert_fails()*
+		Run {cmd} and add an error message to |v:errors| if it does
+		NOT produce an error.
+		When {error} is given it must match |v:errmsg|.
+
 assert_false({actual} [, {msg}])				*assert_false()*
 		When {actual} is not false an error message is added to
 		|v:errors|, like with |assert_equal()|.

src/nvim/eval.c

@@ -6680,6 +6680,7 @@ static struct fst {
   { "asin",              1, 1, f_asin },    // WJMc
   { "assert_equal",      2, 3, f_assert_equal },
   { "assert_exception",  1, 2, f_assert_exception },
+  { "assert_fails",      1, 2, f_assert_fails },
   { "assert_false",      1, 2, f_assert_false },
   { "assert_true",       1, 2, f_assert_true },
   { "atan",              1, 1, f_atan },
@@ -7667,6 +7668,43 @@ static void f_assert_exception(typval_T *argvars, typval_T *rettv)
   }
 }
 
+/// "assert_fails(cmd [, error])" function
+static void f_assert_fails(typval_T *argvars, typval_T *rettv)
+{
+  char_u *cmd = get_tv_string_chk(&argvars[0]);
+  garray_T    ga;
+
+  called_emsg = false;
+  suppress_errthrow = true;
+  emsg_silent = true;
+  do_cmdline_cmd((char *)cmd);
+  if (!called_emsg) {
+    prepare_assert_error(&ga);
+    ga_concat(&ga, (char_u *)"command did not fail: ");
+    ga_concat(&ga, cmd);
+    assert_error(&ga);
+    ga_clear(&ga);
+  } else if (argvars[1].v_type != VAR_UNKNOWN) {
+    char_u buf[NUMBUFLEN];
+    char *error = (char *)get_tv_string_buf_chk(&argvars[1], buf);
+
+    if (error == NULL
+        || strstr((char *)vimvars[VV_ERRMSG].vv_str, error) == NULL) {
+      prepare_assert_error(&ga);
+      fill_assert_error(&ga, &argvars[2], NULL, &argvars[1],
+                        &vimvars[VV_ERRMSG].vv_tv);
+      assert_error(&ga);
+      ga_clear(&ga);
+    }
+  }
+
+  called_emsg = false;
+  suppress_errthrow = false;
+  emsg_silent = false;
+  emsg_on_display = false;
+  set_vim_var_string(VV_ERRMSG, NULL, 0);
+}
+
 // Common for assert_true() and assert_false().
 static void assert_bool(typval_T *argvars, bool is_true)
 {

src/nvim/version.c

@@ -119,7 +119,7 @@ static int included_patches[] = {
   1570,
   1569,
   1568,
-  // 1567,
+  1567,
   // 1566 NA
   // 1565,
   // 1564,
@@ -590,7 +590,7 @@ static int included_patches[] = {
   // 1099 NA
   // 1098 NA
   // 1097,
-  // 1096,
+  1096,
   // 1095 NA
   // 1094,
   1093,

test/functional/legacy/assert_spec.lua

@@ -142,4 +142,22 @@ describe('assert function:', function()
       })
     end)
   end)
+
+  -- assert_fails({cmd}, [, {error}])
+  describe('assert_fails', function()
+    it('should change v:errors when error does not match v:errmsg', function()
+      execute([[call assert_fails('xxx', {})]])
+      expected_errors({"Expected {} but got 'E731: using Dictionary as a String'"})
+    end)
+
+    it('should not change v:errors when cmd errors', function()
+      call('assert_fails', 'NonexistentCmd')
+      expected_empty()
+    end)
+
+    it('should change v:errors when cmd succeeds', function()
+      call('assert_fails', 'call empty("")')
+      expected_errors({'command did not fail: call empty("")'})
+    end)
+  end)
 end)