Fix hlint line/column indexes (#705)

lua/lint/linters/hlint.lua

@@ -12,10 +12,10 @@ return {
     local items = #output > 0 and vim.json.decode(output) or {}
     for _, item in ipairs(items) do
       table.insert(diagnostics, {
-        lnum = item.startLine,
-        col = item.startColumn,
-        end_lnum = item.endLine,
-        end_col = item.endColumn,
+        lnum = item.startLine - 1,
+        col = item.startColumn - 1,
+        end_lnum = item.endLine - 1,
+        end_col = item.endColumn - 1,
         severity = severities[item.severity:lower()],
         source = "hlint",
         message = item.hint .. (item.to ~= vim.NIL and (": " .. item.to) or ""),

spec/hlint_spec.lua

@@ -11,10 +11,10 @@ describe("linter.hlint", function()
     ]])
     assert.are.same(#result, 1)
     local expected = {
-      lnum = 2,
-      col = 1,
-      end_lnum = 2,
-      end_col = 1,
+      lnum = 1,
+      col = 0,
+      end_lnum = 1,
+      end_col = 0,
       severity = vim.diagnostic.severity.ERROR,
       source = "hlint",
       message = "Parse error: possibly incorrect indentation or mismatched brackets",
@@ -34,10 +34,10 @@ describe("linter.hlint", function()
     ]])
     assert.are.same(#result, 1)
     local expected = {
-      lnum = 1,
-      col = 1,
-      end_lnum = 1,
-      end_col = 17,
+      lnum = 0,
+      col = 0,
+      end_lnum = 0,
+      end_col = 16,
       severity = vim.diagnostic.severity.WARN,
       source = "hlint",
       message = "Use concatMap: concatMap f x",