feat: add octo review browse to browse a pull request

Add a new command `Octo review browse` which opens the review layout for
a PR but does not start a review.

This is handy when you want to look over the changes in a PR but do not
necessary want to review it.

When you are in a Review layout initiated by `Octo review browse` you
can intuitively convert it into an active review session with `Octo
review start`.

Its invalid to call `Octo review browse` after `Octo review start` and
the user must either submit or discard the active review to enter the
browse state again.

Closes: pwntester#829

Signed-off-by: ldelossa <[email protected]>

lua/octo/commands.lua

@@ -301,6 +301,9 @@ function M.setup()
       end,
     },
     review = {
+      browse = function()
+        reviews.browse_review()
+      end,
       start = function()
         reviews.start_review()
       end,

lua/octo/reviews/init.lua

@@ -51,6 +51,36 @@ function Review:create(callback)
   }
 end
 
+-- Get review threads without start a review.
+function Review:populate_threads(callback)
+  local query =
+    graphql("review_threads_query", self.pull_request.owner, self.pull_request.name, self.pull_request.number)
+		-- print query to file /tmp/query
+		local file = io.open("/tmp/query", "w")
+		file:write(query)
+		file:close()
+
+  gh.run {
+    args = { "api", "graphql", "-f", string.format("query=%s", query) },
+    cb = function(output, stderr)
+      if stderr and not utils.is_blank(stderr) then
+        utils.error(stderr)
+      elseif output then
+        local resp = vim.fn.json_decode(output)
+        callback(resp)
+      end
+    end,
+  }
+end
+
+function Review:browse()
+  self:populate_threads(function(resp)
+    local threads = resp.data.repository.pullRequest.reviewThreads.nodes
+    self:update_threads(threads)
+    self:initiate()
+  end)
+end
+
 -- Starts a new review
 function Review:start()
   self:create(function(resp)
@@ -573,12 +603,34 @@ local function get_pr_from_buffer_or_current_branch(cb)
     cb(pull_request)
   else
     pull_request = utils.get_pull_request_for_current_branch(cb)
+    cb(pull_request)
+  end
+end
+
+function M.browse_review()
+  local current_review = M.get_current_review()
+
+  if current_review and current_review.id ~= -1 then
+    vim.notify("Cannot browse when a review has been started", vim.log.levels.ERROR)
+    return
   end
+
+  get_pr_from_buffer_or_current_branch(function(pull_request)
+    current_review = Review:new(pull_request)
+    current_review:browse()
+  end)
 end
 
 function M.start_review()
+  -- its possible we are already browsing a review with 'Octo review browse'
+  local current_review = M.get_current_review()
+  if current_review then
+    current_review:start()
+    return
+  end
+
   get_pr_from_buffer_or_current_branch(function(pull_request)
-    local current_review = Review:new(pull_request)
+    current_review = Review:new(pull_request)
     current_review:start()
   end)
 end
@@ -599,7 +651,7 @@ end
 
 function M.discard_review()
   local current_review = M.get_current_review()
-  if current_review then
+  if current_review and current_review.id ~= -1 then
     current_review:discard()
   else
     utils.error "Please start or resume a review first"
@@ -608,7 +660,7 @@ end
 
 function M.submit_review()
   local current_review = M.get_current_review()
-  if current_review then
+  if current_review and current_review.id ~= -1 then
     current_review:collect_submit_info()
   else
     utils.error "Please start or resume a review first"