vim-patch:7.4.1092

Problem:    It is not simple to test for an exception and give a proper error
            message.
Solution:   Add assert_exception().

a803c7f940

runtime/doc/eval.txt

@@ -1788,9 +1788,10 @@ arglistid( [{winnr} [, {tabnr}]])
 				Number	argument list id
 argv( {nr})			String	{nr} entry of the argument list
 argv( )				List	the argument list
-assert_equal( {exp}, {act} [, {msg}]) none    assert that {exp} equals {act}
+assert_equal( {exp}, {act} [, {msg}]) none  assert {exp} equals {act}
-assert_false( {actual} [, {msg}])     none    assert that {actual} is false
+assert_exception({error} [, {msg}])   none  assert {error} is in v:exception
-assert_true( {actual} [, {msg}])      none    assert that {actual} is true
+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}
 atan( {expr})			Float	arc tangent of {expr}
 atan2( {expr}, {expr})		Float   arc tangent of {expr1} / {expr2}
@@ -2245,7 +2246,20 @@ assert_equal({expected}, {actual}, [, {msg}])
 <		Will result in a string to be added to |v:errors|:
 	test.vim line 12: Expected 'foo' but got 'bar' ~
 
-assert_false({actual}, [, {msg}])				*assert_false()*
+assert_exception({error} [, {msg}])			*assert_exception()*
+		When v:exception does not contain the string {error} an error
+		message is added to |v:errors|.
+		This can be used to assert that a command throws an exception.
+		Using the error number, followed by a colon, avoids problems
+		with translations: >
+			try
+			  commandthatfails
+			  call assert_false(1, 'command should have failed')
+			catch
+			  call assert_exception('E492:')
+			endtry
+
+assert_false({actual} [, {msg}])				*assert_false()*
 		When {actual} is not false an error message is added to
 		|v:errors|, like with |assert_equal()|.
 		A value is false when it is zero or |v:false|. When "{actual}" 
@@ -2253,7 +2267,7 @@ assert_false({actual}, [, {msg}])				*assert_false()*
 		When {msg} is omitted an error in the form "Expected False but
 		got {actual}" is produced.
 
-assert_true({actual}, [, {msg}])				*assert_true()*
+assert_true({actual} [, {msg}])					*assert_true()*
 		When {actual} is not true an error message is added to
 		|v:errors|, like with |assert_equal()|.
 		A value is true when it is a non-zero number or |v:true|.  

src/nvim/eval.c

@@ -6665,6 +6665,7 @@ static struct fst {
   { "argv",              0, 1, f_argv },
   { "asin",              1, 1, f_asin },    // WJMc
   { "assert_equal",      2, 3, f_assert_equal },
+  { "assert_exception",  1, 2, f_assert_exception },
   { "assert_false",      1, 2, f_assert_false },
   { "assert_true",       1, 2, f_assert_true },
   { "atan",              1, 1, f_atan },
@@ -7628,6 +7629,26 @@ static void f_assert_equal(typval_T *argvars, typval_T *rettv)
   }
 }
 
+/// "assert_exception(string[, msg])" function
+static void f_assert_exception(typval_T *argvars, typval_T *rettv)
+{
+  garray_T ga;
+
+  char *error = (char *)get_tv_string_chk(&argvars[0]);
+  if (vimvars[VV_EXCEPTION].vv_str == NULL) {
+    prepare_assert_error(&ga);
+    ga_concat(&ga, (char_u *)"v:exception is not set");
+    assert_error(&ga);
+    ga_clear(&ga);
+  } else if (strstr((char *)vimvars[VV_EXCEPTION].vv_str, error) == NULL) {
+    prepare_assert_error(&ga);
+    fill_assert_error(&ga, &argvars[1], NULL, &argvars[0],
+                      &vimvars[VV_EXCEPTION].vv_tv);
+    assert_error(&ga);
+    ga_clear(&ga);
+  }
+}
+
 // Common for assert_true() and assert_false().
 static void assert_bool(typval_T *argvars, bool is_true)
 {

src/nvim/version.c

@@ -585,7 +585,7 @@ static int included_patches[] = {
   // 1095 NA
   // 1094,
   1093,
-  // 1092,
+  1092,
   // 1091,
   // 1090,
   1089,