fn add()

in guppy/src/graph/build.rs [419:513]
88 lines of code
9 McCabe index (conditional complexity)

    fn add(&mut self, target: Target) -> Result<(), Error> {
        use std::collections::btree_map::Entry;

        // Figure out the id and kind using target.kind and target.crate_types.
        let mut target_kinds = target.kind;
        let target_name = target.name.into_boxed_str();
        let crate_types = SortedSet::new(target.crate_types);

        // The "proc-macro" crate type cannot mix with any other types or kinds.
        if target_kinds.len() > 1 && Self::is_proc_macro(&target_kinds) {
            return Err(Error::PackageGraphConstructError(format!(
                "for package {}, proc-macro mixed with other kinds ({:?})",
                self.package_id, target_kinds
            )));
        }
        if crate_types.len() > 1 && Self::is_proc_macro(&crate_types) {
            return Err(Error::PackageGraphConstructError(format!(
                "for package {}, proc-macro mixed with other crate types ({})",
                self.package_id, crate_types
            )));
        }

        let (id, kind, lib_name) = if target_kinds.len() > 1 {
            // multiple kinds always means a library target.
            (
                OwnedBuildTargetId::Library,
                BuildTargetKindImpl::LibraryOrExample(crate_types),
                Some(target_name),
            )
        } else if let Some(target_kind) = target_kinds.pop() {
            let (id, lib_name) = match target_kind.as_str() {
                "custom-build" => (OwnedBuildTargetId::BuildScript, Some(target_name)),
                "bin" => (OwnedBuildTargetId::Binary(target_name), None),
                "example" => (OwnedBuildTargetId::Example(target_name), None),
                "test" => (OwnedBuildTargetId::Test(target_name), None),
                "bench" => (OwnedBuildTargetId::Benchmark(target_name), None),
                _other => {
                    // Assume that this is a library crate.
                    (OwnedBuildTargetId::Library, Some(target_name))
                }
            };

            let kind = match &id {
                OwnedBuildTargetId::Library => {
                    if crate_types.as_slice() == ["proc-macro"] {
                        BuildTargetKindImpl::ProcMacro
                    } else {
                        BuildTargetKindImpl::LibraryOrExample(crate_types)
                    }
                }
                OwnedBuildTargetId::Example(_) => {
                    BuildTargetKindImpl::LibraryOrExample(crate_types)
                }
                _ => {
                    // The crate_types must be exactly "bin".
                    if crate_types.as_slice() != ["bin"] {
                        return Err(Error::PackageGraphConstructError(format!(
                            "for package {}: build target '{:?}' has invalid crate types '{}'",
                            self.package_id, id, crate_types,
                        )));
                    }
                    BuildTargetKindImpl::Binary
                }
            };

            (id, kind, lib_name)
        } else {
            return Err(Error::PackageGraphConstructError(format!(
                "for package ID '{}': build target '{}' has no kinds",
                self.package_id, target_name
            )));
        };

        match self.targets.entry(id) {
            Entry::Occupied(occupied) => {
                return Err(Error::PackageGraphConstructError(format!(
                    "for package ID '{}': duplicate build targets for {:?}",
                    self.package_id,
                    occupied.key()
                )));
            }
            Entry::Vacant(vacant) => {
                vacant.insert(BuildTargetImpl {
                    kind,
                    lib_name,
                    required_features: target.required_features,
                    path: target.src_path.into_boxed_path(),
                    edition: target.edition.into_boxed_str(),
                    doc_tests: target.doctest,
                });
            }
        }

        Ok(())
    }