How to use graphlib - 10 common examples

export function exampleWithLoop () {
  //
  //  f -------,    b<-,
  //  a -- b -- c -- e `
  //    `------ d -'
  //              \
  //      

// Add an implicit dependency on core, if core is not explicitly listed.
    if (coreLoaded && name !== 'core' && ![...after, ...before].includes('core')) {
      after.push('core');
    }

    // Add the edges.
    before.forEach(b => graph.setEdge(name, b));
    after.forEach(a => graph.setEdge(a, name));
  }

  // Sort plugins topologically.
  const orderedPlugins = alg.topsort(graph).map(node => graph.node(node) as EthqlPlugin);

  const sources = graph.sources();
  if (sources.length === 0 || !alg.isAcyclic(graph)) {
    throw new Error(ERR_MSG_NO_ROOT);
  } else if (sources.length > 1) {
    throw new Error(ERR_MSG_MANY_ROOTS(sources));
  }

  console.log(`⚒   Bootstrapping with plugins: ${orderedPlugins.map(p => p.name).join(', ')}.`);

  // Merge schemas, resolvers, serviceDefinitions from all plugins.
  let merged: MergeResult = { config: runtimeConfig, schema: [], resolvers: {}, serviceDefinitions: {} };
  for (let plugin of orderedPlugins) {
    if (typeof plugin.resolvers === 'function') {
      plugin.resolvers = plugin.resolvers(merged.resolvers);
    }
    merged = deepmerge.all([merged, plugin]) as MergeResult;
  }

// Add the node.
    graph.setNode(name, plugin);

    // Add an implicit dependency on core, if core is not explicitly listed.
    if (coreLoaded && name !== 'core' && ![...after, ...before].includes('core')) {
      after.push('core');
    }

    // Add the edges.
    before.forEach(b => graph.setEdge(name, b));
    after.forEach(a => graph.setEdge(a, name));
  }

  // Sort plugins topologically.
  const orderedPlugins = alg.topsort(graph).map(node => graph.node(node) as EthqlPlugin);

  const sources = graph.sources();
  if (sources.length === 0 || !alg.isAcyclic(graph)) {
    throw new Error(ERR_MSG_NO_ROOT);
  } else if (sources.length > 1) {
    throw new Error(ERR_MSG_MANY_ROOTS(sources));
  }

  console.log(`⚒   Bootstrapping with plugins: ${orderedPlugins.map(p => p.name).join(', ')}.`);

  // Merge schemas, resolvers, serviceDefinitions from all plugins.
  let merged: MergeResult = { config: runtimeConfig, schema: [], resolvers: {}, serviceDefinitions: {} };
  for (let plugin of orderedPlugins) {
    if (typeof plugin.resolvers === 'function') {
      plugin.resolvers = plugin.resolvers(merged.resolvers);
    }

(session) => {
      // #TODO: this graph is quite some antipattern to functional
      // programming...
      const nodes = session.Node.all().toModelArray();

      const graph = Graph.getInstance();
      let sorted;
      try {
        const order = GraphAlgorithms.topsort(graph);
        sorted = nodes.sort((a, b) => order.findIndex((id) => id === a.id)
          - order.findIndex((id) => id === b.id));
      } catch (error) {
        // #TODO not sure how to check this:
        // if (error instanceof CycleException) {
        sorted = nodes;
        console.warn('You probably have a circularity in your graph...');
      }
      return sorted.map((node) => {
        const parameters = node.parameters && node.parameters.toRefArray();
        return {...node.ref, parameters};
      });
    }

static async buildGraphFromScope(scope: Scope): Promise {
    const graph = new Graph();
    const allModelComponents: ModelComponent[] = await scope.list();
    const buildGraphP = allModelComponents.map(async modelComponent => {
      const buildVersionP = modelComponent.listVersions().map(async versionNum => {
        const version = await modelComponent.loadVersion(versionNum, scope.objects);
        if (!version) {
          // a component might be in the scope with only the latest version
          return;
        }
        const id = modelComponent.toBitId().changeVersion(versionNum);
        this._addDependenciesToGraph(id, graph, version);
      });
      await Promise.all(buildVersionP);
    });
    await Promise.all(buildGraphP);
    return graph;
  }

export const draw = function(text, id) {
  conf = getConfig().state;
  parser.yy.clear();
  parser.parse(text);
  logger.debug('Rendering diagram ' + text);

  // /// / Fetch the default direction, use TD if none was found
  const diagram = d3.select(`[id='${id}']`);
  insertMarkers(diagram);

  // // Layout graph, Create a new directed graph
  const graph = new graphlib.Graph({
    multigraph: false,
    compound: true,
    // acyclicer: 'greedy',
    rankdir: 'RL'
    // ranksep: '20'
  });

  // // Default to assigning a new object as a label for each new edge.
  graph.setDefaultEdgeLabel(function() {
    return {};
  });

  const rootDoc = stateDb.getRootDoc();
  renderDoc(rootDoc, diagram);

  const padding = conf.padding;

if (!compileGraph.hasNode(name)) {
            compileGraph.setNode(name);
          }
        }
        if (!compileGraph.hasNode(toName)) {
          compileGraph.setNode(toName);
        }

        // reverse!
        compileGraph.setEdge({v:toName, w:fromName});
      });
    });

    // Apply topological sorting, Start at the leafs of the graphs (e.g. atoms) and go further
    // up in the hierarchy
    const o = graphlib.alg.topsort(compileGraph);
    return this.nodes2patterns(o);
  },

export function topologicalSortComponentDependencies(componentWithDependencies: ComponentWithDependencies): void {
  const { graphDeps } = buildComponentsGraph([
    componentWithDependencies.component,
    ...componentWithDependencies.allDependencies
  ]);
  const componentId = componentWithDependencies.component.id.toString();
  let sortedComponents;
  if (!graphLib.alg.isAcyclic(graphDeps)) {
    const circle = graphLib.alg.findCycles(graphDeps);
    throw new GeneralError(
      `unable to topological sort dependencies of ${componentId}, it has the following cyclic dependencies\n${circle}`
    );
  }
  try {
    sortedComponents = graphLib.alg.topsort(graphDeps);
    const sortedComponentsIds = sortedComponents.map(s => graphDeps.node(s));
    const sortedDependenciesIds = R.tail(sortedComponentsIds); // the first one is the component itself
    const dependencies = sortedDependenciesIds.map(depId => {
      const matchDependency = componentWithDependencies.dependencies.find(dependency => dependency.id.isEqual(depId));
      if (!matchDependency) throw new Error(`topologicalSortComponentDependencies, ${depId.toString()} is missing`);
      return matchDependency;
    });
    componentWithDependencies.dependencies = dependencies;
  } catch (err) {
    throw new GeneralError(`unable to topological sort dependencies of ${componentId}. Original error: ${err.message}`);

}
      // there are circles but they are all from the same scope, add them to groupedArraySorted
      // first, then, remove from the graph, so it will be possible to execute topsort
      cycles.forEach(cycle => {
        cycle.forEach(node => {
          const id = graph.node(node);
          addToGroupedSorted(id);
          graph.removeNode(node);
        });
      });
    }
    // @todo: optimize in case each one of the ids has all its dependencies from the same scope,
    // return groupedArrayFormat
    let sortedComponents;
    try {
      sortedComponents = graphLib.alg.topsort(graph);
    } catch (err) {
      // should never arrive here, it's just a precaution, as topsort doesn't fail nicely
      logger.error(err);
      throw new Error(`fatal: graphlib was unable to topsort the components. circles: ${cycles}`);
    }
    const sortedComponentsIds = sortedComponents.map(s => graph.node(s)).reverse();
    sortedComponentsIds.forEach(id => addToGroupedSorted(id));

    return groupedArraySorted;
  }

if (!succIds) throw new InternalError(`id '${id}' not found`);
            const deps = succIds.map((sId) => {
                const isHard = hardSet.delete(sId);
                return { id: sId, type: isHard ? "hard" : "soft" };
            });
            if (hardSet.size !== 0) {
                throw new InternalError(`Internal consistency check failed: ` +
                    `not all hardDeps are successors`);
            }
            const entry: EPDependencies[string] = { detail: detail(node), deps };
            if (node.element) entry.elementId = node.element.id;
            return entry;
        };

        const ret: EPDependencies = {};
        const ids = alg.isAcyclic(this.graph) ?
            alg.topsort(this.graph) : this.graph.nodes();

        // Insert starting with leaves for a more human-readable ordering
        for (let i = ids.length - 1; i >= 0; i--) {
            const id = ids[i];
            const node = this.getNode(id);
            ret[id] = getDeps(node, id);
        }
        return ret;
    }