make notebook id available to notebook code

src/evaluation/WorkspaceManager.jl

@@ -57,6 +57,7 @@ function make_workspace((session, notebook)::SN; force_offline::Bool=false)::Wor
         pid
     end
 
+    Distributed.remotecall_eval(Main, [pid], :(PlutoRunner.notebook_id[] = $(notebook.notebook_id)))
     log_channel = Core.eval(Main, quote
         $(Distributed).RemoteChannel(() -> eval(:(Main.PlutoRunner.log_channel)), $pid)
     end)

src/runner/PlutoRunner.jl

@@ -17,7 +17,7 @@ import Distributed
 import Base64
 import FuzzyCompletions: Completion, ModuleCompletion, PropertyCompletion, FieldCompletion, completions, completion_text, score
 import Base: show, istextmime
-import UUIDs: UUID
+import UUIDs: UUID, uuid4
 import Logging
 
 export @bind
@@ -41,6 +41,11 @@ ObjectDimPair = Tuple{ObjectID,Int64}
 "The current workspace where your variables live. See [`move_vars`](@ref)."
 current_module = Main
 
+"""
+`PlutoRunner.notebook_id[]` gives you the notebook ID used to identify a session.
+"""
+const notebook_id = Ref{UUID}(uuid4())
+
 function set_current_module(newname)
     # Revise.jl support
     if isdefined(current_module, :Revise) &&

test/Dynamic.jl

@@ -148,4 +148,21 @@ end
         @test occursin("square root", Pluto.PlutoRunner.doc_fetcher("Base.sqrt")[1])
         @test occursin("No documentation found", Pluto.PlutoRunner.doc_fetcher("Base.findmeta")[1])
     end
+
+    @testset "PlutoRunner API" begin
+        fakeclient = ClientSession(:fake, nothing)
+        🍭 = ServerSession()
+        🍭.options.evaluation.workspace_use_distributed = true
+        🍭.connected_clients[fakeclient.id] = fakeclient
+
+        notebook = Notebook([
+            Cell("PlutoRunner.notebook_id[] |> Text"),
+        ])
+        fakeclient.connected_notebook = notebook
+
+        update_save_run!(🍭, notebook, notebook.cells)
+        @test notebook.cells[1].output.body == notebook.notebook_id |> string
+
+        WorkspaceManager.unmake_workspace((🍭, notebook))
+    end
 end

test/WorkspaceManager.jl

@@ -11,6 +11,7 @@ import Pluto: update_save_run!, WorkspaceManager, ClientSession, ServerSession,
         fakeclientA = ClientSession(:fakeA, nothing)
         fakeclientB = ClientSession(:fakeB, nothing)
         🍭 = ServerSession()
+        🍭.options.evaluation.workspace_use_distributed = true
         🍭.connected_clients[fakeclientA.id] = fakeclientA
         🍭.connected_clients[fakeclientB.id] = fakeclientB