Fix match, can_match error handling

lua/gesture/command.lua

@@ -22,8 +22,19 @@ function M.draw(raw_opts)
   end
 
   local ctx = state:action_context()
-  local can_match = state.matcher:can_match(ctx)
-  local nowait_gesture = can_match and state.matcher:nowait_match(ctx) or nil
+
+  local can_match, can_match_err = state.matcher:can_match(ctx)
+  if can_match_err then
+    state:close()
+    require("gesture.vendor.misclib.message").error(can_match_err)
+  end
+
+  local nowait_gesture, nowait_err = state.matcher:nowait_match(ctx, can_match)
+  if nowait_err then
+    state:close()
+    require("gesture.vendor.misclib.message").error(nowait_err)
+  end
+
   if nowait_gesture then
     state:close()
     local err = nowait_gesture:execute(ctx)
@@ -33,7 +44,12 @@ function M.draw(raw_opts)
     return
   end
 
-  local gesture = can_match and state.matcher:match(ctx) or nil
+  local gesture, match_err = state.matcher:match(ctx, can_match)
+  if match_err then
+    state:close()
+    require("gesture.vendor.misclib.message").error(match_err)
+  end
+
   state.view:render_input(ctx.inputs, gesture, can_match, opts.show_board)
 end
 
@@ -53,7 +69,12 @@ function M.finish()
 
   local ctx = state:action_context()
   state:close()
-  local gesture = state.matcher:match(ctx)
+
+  local gesture, match_err = state.matcher:match(ctx, true)
+  if match_err then
+    require("gesture.vendor.misclib.message").error(match_err)
+  end
+
   if gesture then
     local err = gesture:execute(ctx)
     if err then

lua/gesture/core/gesture_info.lua

@@ -36,25 +36,27 @@ function GestureInfo.new(info)
   local input_defs
   local strs
   local match
+  local can_match
   local equals
   if info.match then
     strs = nil
-    match = info.match
+    match = function(ctx)
+      return can_match(ctx) and info.match(ctx)
+    end
     equals = function(g)
       return name == g.name
     end
   else
     input_defs = require("gesture.core.input_definitions").new(info.inputs or {})
     strs = input_defs:strings()
     match = function(ctx)
-      return input_defs:match(ctx.inputs)
+      return can_match(ctx) and input_defs:match(ctx.inputs)
     end
     equals = function(g)
       return input_defs:equals(g._input_defs)
     end
   end
 
-  local can_match
   if info.can_match then
     can_match = info.can_match
   elseif info.match then
@@ -69,12 +71,12 @@ function GestureInfo.new(info)
 
   local tbl = {
     name = name,
-    match = match,
-    can_match = can_match,
     equals = equals,
     nowait = info.nowait or false,
     buffer = bufnr,
     strs = strs,
+    _match = match,
+    _can_match = can_match,
     _action = action,
     _input_defs = input_defs,
   }
@@ -89,4 +91,20 @@ function GestureInfo.execute(self, ctx)
   return nil
 end
 
+function GestureInfo.match(self, ctx)
+  local ok, result = pcall(self._match, ctx)
+  if not ok then
+    return false, result
+  end
+  return result, nil
+end
+
+function GestureInfo.can_match(self, ctx)
+  local ok, result = pcall(self._can_match, ctx)
+  if not ok then
+    return false, result
+  end
+  return result, nil
+end
+
 return GestureInfo

lua/gesture/core/gesture_map.lua

@@ -47,7 +47,10 @@ function GestureMap.match(self, bufnr, ctx, nowait)
     make_key(nil, nowait, input_strs),
   }
   for _, key in ipairs(keys) do
-    local gesture = self:_match(key, ctx)
+    local gesture, err = self:_match(key, ctx)
+    if err then
+      return nil, err
+    end
     if gesture then
       return gesture
     end
@@ -87,7 +90,10 @@ function GestureMap.can_match(self, bufnr, ctx)
     },
   }
   for _, key_pair in ipairs(key_pairs) do
-    local matched = self:_can_match(key_pair[1], key_pair[2], ctx)
+    local matched, err = self:_can_match(key_pair[1], key_pair[2], ctx)
+    if err then
+      return false, err
+    end
     if matched then
       return matched
     end
@@ -99,8 +105,14 @@ end
 function GestureMap._can_match(self, nowait_key, key, ctx)
   for k, gestures in pairs(self._map) do
     local key_matched = vim.startswith(k, nowait_key) or vim.startswith(k, key)
-    if key_matched and gestures:can_match(ctx) then
-      return true
+    if key_matched then
+      local ok, err = gestures:can_match(ctx)
+      if err then
+        return false, err
+      end
+      if ok then
+        return true
+      end
     end
   end
   return false

lua/gesture/core/gestures.lua

@@ -18,7 +18,11 @@ end
 
 function Gestures.can_match(self, ctx)
   for _, gesture in ipairs(self._gestures) do
-    if gesture.can_match(ctx) then
+    local ok, err = gesture:can_match(ctx)
+    if err then
+      return false, err
+    end
+    if ok then
       return true
     end
   end
@@ -27,7 +31,11 @@ end
 
 function Gestures.match(self, ctx)
   for _, gesture in ipairs(self._gestures) do
-    if gesture.can_match(ctx) and gesture.match(ctx) then
+    local ok, err = gesture:match(ctx)
+    if err then
+      return nil, err
+    end
+    if ok then
       return gesture
     end
   end

lua/gesture/core/matcher.lua

@@ -12,11 +12,17 @@ function Matcher.new(bufnr)
   return setmetatable(tbl, Matcher)
 end
 
-function Matcher.nowait_match(self, ctx)
+function Matcher.nowait_match(self, ctx, can_match)
+  if not can_match then
+    return nil
+  end
   return self._gesture_map:match(self._bufnr, ctx, true)
 end
 
-function Matcher.match(self, ctx)
+function Matcher.match(self, ctx, can_match)
+  if not can_match then
+    return nil
+  end
   return self._gesture_map:match(self._bufnr, ctx, false)
 end
 

spec/lua/gesture/init_spec.lua

@@ -551,6 +551,39 @@ describe("gesture.draw()", function()
 
     assert.no.shown_in_view("RIGHT")
   end)
+
+  it("cleanups on match error", function()
+    gesture.register({
+      match = function()
+        error("match error")
+      end,
+      action = "",
+    })
+
+    local ok, err = pcall(function()
+      gesture.draw()
+    end)
+    assert.is_false(ok)
+    assert.match("match error", err)
+    assert.window_count(1)
+  end)
+
+  it("cleanups on can_match error", function()
+    gesture.register({
+      inputs = { gesture.down() },
+      can_match = function()
+        error("can_match error")
+      end,
+      action = "",
+    })
+
+    local ok, err = pcall(function()
+      gesture.draw()
+    end)
+    assert.is_false(ok)
+    assert.match("can_match error", err)
+    assert.window_count(1)
+  end)
 end)
 
 describe("gesture.finish()", function()
@@ -575,6 +608,31 @@ describe("gesture.finish()", function()
     assert.is_false(called)
   end)
 
+  it("raises error if match raises error", function()
+    local for_finish = false
+    gesture.register({
+      match = function()
+        if not for_finish then
+          return nil
+        end
+        error("match error")
+      end,
+      can_match = function()
+        return true
+      end,
+      action = "",
+    })
+
+    gesture.draw()
+
+    local ok, err = pcall(function()
+      for_finish = true
+      gesture.finish()
+    end)
+    assert.is_false(ok)
+    assert.match("match error", err)
+  end)
+
   it("raises error if action raises error", function()
     gesture.register({
       inputs = { gesture.down() },