fix: evict memoized derived values when files are removed

src/public.jl

@@ -263,9 +263,20 @@ function remove_file!(jw::JuliaWorkspace, uri::URI)
 
     process_from_dynamic(jw)
     _remove_file!(jw, uri)
+    _evict_derived_for_uris!(jw, (uri,))
     _reconcile!(jw)
 end
 
+# Evict all memoized derived values keyed by any of the given (removed) URIs.
+# Without this they would stay in the Salsa storage for the lifetime of the
+# workspace, since nothing queries a removed URI again.
+function _evict_derived_for_uris!(jw::JuliaWorkspace, uris)
+    uri_set = Set{URI}(uris)
+    Salsa.evict_derived!(jw.runtime) do key
+        any(arg -> arg isa URI && arg in uri_set, key.args)
+    end
+end
+
 # Input-only removal. Does not drain results or reconcile.
 function _remove_file!(jw::JuliaWorkspace, uri::URI)
     files = input_files(jw.runtime)
@@ -293,14 +304,18 @@ function remove_all_children!(jw::JuliaWorkspace, uri::URI)
 
     uri_as_string = string(uri)
 
+    removed = URI[]
     for file in files
         file_as_string = string(file)
 
         if startswith(file_as_string, uri_as_string)
             _remove_file!(jw, file)
+            push!(removed, file)
         end
     end
 
+    isempty(removed) || _evict_derived_for_uris!(jw, removed)
+
     _reconcile!(jw)
 end
 
@@ -346,6 +361,7 @@ function clear_indirect_file!(jw::JuliaWorkspace, uri::URI)
     process_from_dynamic(jw)
 
     _clear_indirect_tracking!(jw, uri)
+    _evict_derived_for_uris!(jw, (uri,))
 
     _reconcile!(jw)
 end

test/test_eviction.jl

@@ -0,0 +1,55 @@
+@testitem "remove_file! evicts derived values for the removed URI" begin
+    using JuliaWorkspaces.URIs2: URI
+    using JuliaWorkspaces: Salsa
+
+    n_entries_for(jw, uri) =
+        Salsa.evict_derived!(key -> any(arg -> isequal(arg, uri), key.args), jw.runtime)
+
+    uri1 = URI("file:///evicttest/src/a.jl")
+    uri2 = URI("file:///evicttest/src/b.jl")
+
+    jw = JuliaWorkspace()
+    add_file!(jw, TextFile(uri1, SourceText("f(x) = x + 1", "julia")))
+    add_file!(jw, TextFile(uri2, SourceText("g(x) = x - 1", "julia")))
+
+    # Populate the derived caches.
+    get_diagnostic(jw, uri1)
+    get_diagnostic(jw, uri2)
+
+    remove_file!(jw, uri1)
+
+    # No derived entry may still be keyed by the removed URI. (The probe uses
+    # evict_derived! itself: it returns the number of matching entries.)
+    @test n_entries_for(jw, uri1) == 0
+
+    # The surviving file is untouched and still queryable.
+    @test get_diagnostic(jw, uri2) isa Vector
+    @test has_file(jw, uri2)
+end
+
+@testitem "remove_all_children! evicts derived values for all removed URIs" begin
+    using JuliaWorkspaces.URIs2: URI
+    using JuliaWorkspaces: Salsa
+
+    n_entries_for(jw, uri) =
+        Salsa.evict_derived!(key -> any(arg -> isequal(arg, uri), key.args), jw.runtime)
+
+    uris = [URI("file:///evictfolder/src/f$i.jl") for i in 1:5]
+    outside = URI("file:///other/src/g.jl")
+
+    jw = JuliaWorkspace()
+    for uri in uris
+        add_file!(jw, TextFile(uri, SourceText("h(x) = x", "julia")))
+    end
+    add_file!(jw, TextFile(outside, SourceText("h(x) = x", "julia")))
+
+    get_diagnostics(jw)
+
+    remove_all_children!(jw, URI("file:///evictfolder"))
+
+    for uri in uris
+        @test n_entries_for(jw, uri) == 0
+    end
+    @test has_file(jw, outside)
+    @test get_diagnostic(jw, outside) isa Vector
+end