API: return non-generic VimL errors

- Return VimL errors instead of generic errors for:
  - nvim_call_function
  - nvim_call_dict_function
- Fix tests which were silently broken before this change.

This violates #6150 where we agreed not to translate API errors.  But
that can be fixed later.

1 files changed, 45 insertions, 17 deletions

diff --git a/test/functional/api/vim_spec.lua b/test/functional/api/vim_spec.lua
index 0ff755b320..d56cf77c5f 100644
--- a/test/functional/api/vim_spec.lua
+++ b/test/functional/api/vim_spec.lua
@@ -5,6 +5,7 @@ local global_helpers = require('test.helpers')
 local NIL = helpers.NIL
 local clear, nvim, eq, neq = helpers.clear, helpers.nvim, helpers.eq, helpers.neq
 local command = helpers.command
+local eval = helpers.eval
 local funcs = helpers.funcs
 local iswin = helpers.iswin
 local meth_pcall = helpers.meth_pcall
@@ -40,20 +41,20 @@ describe('api', function()
       os.remove(fname)
     end)
 
-    it("parse error: fails (specific error), does NOT update v:errmsg", function()
-      -- Most API methods return generic errors (or no error) if a VimL
-      -- expression fails; nvim_command returns the VimL error details.
+    it('VimL validation error: fails with specific error', function()
       local status, rv = pcall(nvim, "command", "bogus_command")
       eq(false, status)                       -- nvim_command() failed.
       eq("E492:", string.match(rv, "E%d*:"))  -- VimL error was returned.
-      eq("", nvim("eval", "v:errmsg"))        -- v:errmsg was not updated.
+      eq('', nvim('eval', 'v:errmsg'))        -- v:errmsg was not updated.
+      eq('', eval('v:exception'))
     end)
 
-    it("runtime error: fails (specific error)", function()
+    it('VimL execution error: fails with specific error', function()
       local status, rv = pcall(nvim, "command_output", "buffer 23487")
       eq(false, status)                 -- nvim_command() failed.
       eq("E86: Buffer 23487 does not exist", string.match(rv, "E%d*:.*"))
-      eq("", nvim("eval", "v:errmsg"))  -- v:errmsg was not updated.
+      eq('', eval('v:errmsg'))  -- v:errmsg was not updated.
+      eq('', eval('v:exception'))
     end)
   end)
 
@@ -109,21 +110,21 @@ describe('api', function()
       eq(':!echo foo\r\n\nfoo'..win_lf..'\n', nvim('command_output', [[!echo foo]]))
     end)
 
-    it("parse error: fails (specific error), does NOT update v:errmsg", function()
+    it('VimL validation error: fails with specific error', function()
       local status, rv = pcall(nvim, "command_output", "bogus commannnd")
       eq(false, status)                 -- nvim_command_output() failed.
       eq("E492: Not an editor command: bogus commannnd",
          string.match(rv, "E%d*:.*"))
-      eq("", nvim("eval", "v:errmsg"))  -- v:errmsg was not updated.
+      eq('', eval('v:errmsg'))  -- v:errmsg was not updated.
       -- Verify NO hit-enter prompt.
       eq({mode='n', blocking=false}, nvim("get_mode"))
     end)
 
-    it("runtime error: fails (specific error)", function()
+    it('VimL execution error: fails with specific error', function()
       local status, rv = pcall(nvim, "command_output", "buffer 42")
       eq(false, status)                 -- nvim_command_output() failed.
       eq("E86: Buffer 42 does not exist", string.match(rv, "E%d*:.*"))
-      eq("", nvim("eval", "v:errmsg"))  -- v:errmsg was not updated.
+      eq('', eval('v:errmsg'))  -- v:errmsg was not updated.
       -- Verify NO hit-enter prompt.
       eq({mode='n', blocking=false}, nvim("get_mode"))
     end)
@@ -149,7 +150,7 @@ describe('api', function()
       local status, rv = pcall(nvim, "eval", "bogus expression")
       eq(false, status)                 -- nvim_eval() failed.
       ok(nil ~= string.find(rv, "Failed to evaluate expression"))
-      eq("", nvim("eval", "v:errmsg"))  -- v:errmsg was not updated.
+      eq('', eval('v:errmsg'))  -- v:errmsg was not updated.
     end)
   end)
 
@@ -160,12 +161,39 @@ describe('api', function()
       eq(17, nvim('call_function', 'eval', {17}))
       eq('foo', nvim('call_function', 'simplify', {'this/./is//redundant/../../../foo'}))
     end)
-    it("VimL error: fails (generic error), does NOT update v:errmsg", function()
-      local status, rv = pcall(nvim, "call_function", "bogus function", {"arg1"})
-      eq(false, status)                 -- nvim_call_function() failed.
-      ok(nil ~= string.find(rv, "Error calling function"))
-      eq("", nvim("eval", "v:errmsg"))  -- v:errmsg was not updated.
+
+    it("VimL validation error: returns specific error, does NOT update v:errmsg", function()
+      expect_err('E117: Unknown function: bogus function', request,
+                 'nvim_call_function', 'bogus function', {'arg1'})
+      expect_err('E119: Not enough arguments for function: atan', request,
+                 'nvim_call_function', 'atan', {})
+      eq('', eval('v:exception'))
+      eq('', eval('v:errmsg'))  -- v:errmsg was not updated.
+    end)
+
+    it("VimL error: returns error details, does NOT update v:errmsg", function()
+      expect_err('E808: Number or Float required', request,
+                 'nvim_call_function', 'atan', {'foo'})
+      expect_err('Invalid channel stream "xxx"', request,
+                 'nvim_call_function', 'chanclose', {999, 'xxx'})
+      expect_err('E900: Invalid channel id', request,
+                 'nvim_call_function', 'chansend', {999, 'foo'})
+      eq('', eval('v:exception'))
+      eq('', eval('v:errmsg'))  -- v:errmsg was not updated.
+    end)
+
+    it("VimL exception: returns exception details, does NOT update v:errmsg", function()
+      source([[
+        function! Foo() abort
+          throw 'wtf'
+        endfunction
+      ]])
+      expect_err('wtf', request,
+                 'nvim_call_function', 'Foo', {})
+      eq('', eval('v:exception'))
+      eq('', eval('v:errmsg'))  -- v:errmsg was not updated.
     end)
+
     it('validates args', function()
       local too_many_args = { 'x', 'x', 'x', 'x', 'x', 'x', 'x', 'x', 'x', 'x', 'x', 'x', 'x', 'x', 'x', 'x', 'x', 'x', 'x', 'x', 'x' }
       source([[
@@ -216,7 +244,7 @@ describe('api', function()
                  'nvim_call_dict_function', 'g:d', 'baz', {1,2})
       expect_err('Not a function: meep', request,
                  'nvim_call_dict_function', 'g:d', 'meep', {1,2})
-      expect_err('Error calling function', request,
+      expect_err('E117: Unknown function: f', request,
                  'nvim_call_dict_function', { f = '' }, 'f', {1,2})
       expect_err('Not a function: f', request,
                  'nvim_call_dict_function', "{ 'f': '' }", 'f', {1,2})