[Transit nodes] Confuse about the parallelism when using transit nodes

[motss]

Summary

If you test out making breaking changes in your ui package again, you'll notice that the caching behavior is now correct. However, tasks are no longer running in parallel.

I am reading the new docs about transit nodes and I don't get it why and how the parallelism works for the case with transit nodes but not with the case without transit nodes.

Please help validate if my graphs below are correct in terms of the execution order with and without transit nodes. Thanks. 🙏

# Note: `dependsOn` in the `Dependencies` has nothing to with `dependsOn` field in `turbo.json`.
# It basically means `a` installed `b` as a dependency package for `a -- dependOn --> `b.

# Example 1
# Dependencies
# a -- dependsOn --> b
# b -- dependsOn --> c

# --- without transit nodes ---
c#build
       b#build
              a#build

# --- with transit nodes ---
a#transit
                       a#build
b#transit
                b#build
c#transit
         c#build

# Example 2
# Dependencies: 
# a & b -- dependsOn --> c

# --- without transit nodes ---

b#build
       a#build
       c#build

# --- with transit nodes ---

a#transit
                a#build
b#transit
         b#build
c#transit
                c#build

Additional information

N/A for the discussion stated above.

Example

N/A

[anthonyshew]

Can you clarify what those examples are supposed to mean? It's impossible to tell what you meant.

[motss]

The examples are the charts drawn to outline the execution order of the turbo tasks which inspired by this page in the official doc, refer to the images below:

[anthonyshew]

The best explanation we're likely able to give is probably from this documentation: https://turbo.build/repo/docs/crafting-your-repository/configuring-tasks#dependent-tasks-that-can-be-ran-in-parallel