1 files changed, 119 insertions, 1 deletions
diff --git a/test/old/testdir/test_let.vim b/test/old/testdir/test_let.vim
index 6fbf305624..0d84164274 100644
--- a/test/old/testdir/test_let.vim
+++ b/test/old/testdir/test_let.vim
@@ -1,5 +1,7 @@
 " Tests for the :let command.
 
+source vim9.vim
+
 func Test_let()
   " Test to not autoload when assigning.  It causes internal error.
   set runtimepath+=./sautest
@@ -385,7 +387,18 @@ END
   call assert_equal(['Text', 'with', 'indent'], text)
 endfunc
 
-" Test for the setting a variable using the heredoc syntax
+func Test_let_interpolated()
+  call assert_equal('{text}', $'{{text}}')
+  call assert_equal('{{text}}', $'{{{{text}}}}')
+  let text = 'text'
+  call assert_equal('text{{', $'{text .. "{{"}')
+  call assert_equal('text{{', $"{text .. '{{'}")
+  call assert_equal('text{{', $'{text .. '{{'}')
+  call assert_equal('text{{', $"{text .. "{{"}")
+endfunc
+
+" Test for the setting a variable using the heredoc syntax.
+" Keep near the end, this messes up highlighting.
 func Test_let_heredoc()
   let var1 =<< END
 Some sample text
@@ -493,4 +506,109 @@ END
   call assert_equal(['     x', '     \y', '     z'], [a, b, c])
 endfunc
 
+" Test for evaluating Vim expressions in a heredoc using {expr}
+" Keep near the end, this messes up highlighting.
+func Test_let_heredoc_eval()
+  let str = ''
+  let code =<< trim eval END
+    let a = {5 + 10}
+    let b = {min([10, 6])} + {max([4, 6])}
+    {str}
+    let c = "abc{str}d"
+  END
+  call assert_equal(['let a = 15', 'let b = 6 + 6', '', 'let c = "abcd"'], code)
+
+  let $TESTVAR = "Hello"
+  let code =<< eval trim END
+    let s = "{$TESTVAR}"
+  END
+  call assert_equal(['let s = "Hello"'], code)
+
+  let code =<< eval END
+    let s = "{$TESTVAR}"
+END
+  call assert_equal(['    let s = "Hello"'], code)
+
+  let a = 10
+  let data =<< eval END
+{a}
+END
+  call assert_equal(['10'], data)
+
+  let x = 'X'
+  let code =<< eval trim END
+    let a = {{abc}}
+    let b = {x}
+    let c = {{
+  END
+  call assert_equal(['let a = {abc}', 'let b = X', 'let c = {'], code)
+
+  let code = 'xxx'
+  let code =<< eval trim END
+    let n = {5 +
+    6}
+  END
+  call assert_equal('xxx', code)
+
+  let code =<< eval trim END
+     let n = {min([1, 2]} + {max([3, 4])}
+  END
+  call assert_equal('xxx', code)
+
+  let lines =<< trim LINES
+      let text =<< eval trim END
+        let b = {
+      END
+  LINES
+  call CheckScriptFailure(lines, 'E1279:')
+
+  let lines =<< trim LINES
+      let text =<< eval trim END
+        let b = {abc
+      END
+  LINES
+  call CheckScriptFailure(lines, 'E1279:')
+
+  let lines =<< trim LINES
+      let text =<< eval trim END
+        let b = {}
+      END
+  LINES
+  call CheckScriptFailure(lines, 'E15:')
+
+  " skipped heredoc
+  if 0
+    let msg =<< trim eval END
+        n is: {n}
+    END
+  endif
+
+  " Test for sourcing a script containing a heredoc with invalid expression.
+  " Variable assignment should fail, if expression evaluation fails
+  new
+  let g:Xvar = 'test'
+  let g:b = 10
+  let lines =<< trim END
+    let Xvar =<< eval CODE
+    let a = 1
+    let b = {5+}
+    let c = 2
+    CODE
+    let g:Count += 1
+  END
+  call setline(1, lines)
+  let g:Count = 0
+  call assert_fails('source', 'E15:')
+  call assert_equal(1, g:Count)
+  call setline(3, 'let b = {abc}')
+  call assert_fails('source', 'E121:')
+  call assert_equal(2, g:Count)
+  call setline(3, 'let b = {abc} + {min([9, 4])} + 2')
+  call assert_fails('source', 'E121:')
+  call assert_equal(3, g:Count)
+  call assert_equal('test', g:Xvar)
+  call assert_equal(10, g:b)
+  bw!
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab