tests: Migrate legacy test 34. (#2849)

test/functional/legacy/034_user_function_spec.lua

@@ -0,0 +1,102 @@
+-- Test for user functions.
+-- Also test an <expr> mapping calling a function.
+-- Also test that a builtin function cannot be replaced.
+-- Also test for regression when calling arbitrary expression.
+
+local helpers = require('test.functional.helpers')
+local feed, insert, source = helpers.feed, helpers.insert, helpers.source
+local clear, execute, expect = helpers.clear, helpers.execute, helpers.expect
+
+describe('user functions, expr-mappings, overwrite protected builtin functions and regression on calling expressions', function()
+  setup(clear)
+
+  it('are working', function()
+    insert('here')
+
+    source([[
+      function Table(title, ...)
+        let ret = a:title
+        let idx = 1
+        while idx <= a:0
+          exe "let ret = ret . a:" . idx
+          let idx = idx + 1
+        endwhile
+        return ret
+      endfunction
+      function Compute(n1, n2, divname)
+        if a:n2 == 0
+          return "fail"
+        endif
+        exe "let g:" . a:divname . " = ". a:n1 / a:n2
+        return "ok"
+      endfunction
+      func Expr1()
+        normal! v
+        return "111"
+      endfunc
+      func Expr2()
+        call search('XX', 'b')
+        return "222"
+      endfunc
+      func ListItem()
+        let g:counter += 1
+        return g:counter . '. '
+      endfunc
+      func ListReset()
+        let g:counter = 0
+        return ''
+      endfunc
+      func FuncWithRef(a)
+        unlet g:FuncRef
+        return a:a
+      endfunc
+      let g:FuncRef=function("FuncWithRef")
+      let counter = 0
+      inoremap <expr> ( ListItem()
+      inoremap <expr> [ ListReset()
+      imap <expr> + Expr1()
+      imap <expr> * Expr2()
+      let retval = "nop"
+      /^here
+    ]])
+    feed('C<C-R>=Table("xxx", 4, "asdf")<cr>')
+    -- Using a actual space will not work as feed() calls dedent on the input.
+    feed('<space><C-R>=Compute(45, 0, "retval")<cr>')
+    feed('<space><C-R>=retval<cr>')
+    feed('<space><C-R>=Compute(45, 5, "retval")<cr>')
+    feed('<space><C-R>=retval<cr>')
+    feed('<space><C-R>=g:FuncRef(333)<cr>')
+    feed('<cr>')
+    feed('XX+-XX<cr>')
+    feed('---*---<cr>')
+    feed('(one<cr>')
+    feed('(two<cr>')
+    feed('[(one again<esc>')
+    execute('call append(line("$"), max([1, 2, 3]))')
+    execute('call extend(g:, {"max": function("min")})')
+    execute('call append(line("$"), max([1, 2, 3]))')
+    execute('try')
+    -- Regression: the first line below used to throw "E110: Missing ')'"
+    -- Second is here just to prove that this line is correct when not
+    -- skipping rhs of &&.
+    execute([[    $put =(0&&(function('tr'))(1, 2, 3))]])
+    execute([[    $put =(1&&(function('tr'))(1, 2, 3))]])
+    execute('catch')
+    execute([[    $put ='!!! Unexpected exception:']])
+    execute('    $put =v:exception')
+    execute('endtry')
+
+    -- Assert buffer contents.
+    expect([[
+      xxx4asdf fail nop ok 9 333
+      XX111-XX
+      ---222---
+      1. one
+      2. two
+      1. one again
+      3
+      3
+      0
+      1]])
+  end)
+end)