Modify `sourcecred load` to save timeline cred

Test plan: Observe changes to the snapshot for example-github-load.
`yarn test --full` passes.

src/cli/load.js

@@ -3,6 +3,7 @@
 
 import mkdirp from "mkdirp";
 import path from "path";
+import chalk from "chalk";
 
 import fs from "fs-extra";
 import stringify from "json-stable-stringify";
@@ -11,13 +12,17 @@ import {repoIdToString, stringToRepoId, type RepoId} from "../core/repoId";
 import dedent from "../util/dedent";
 import type {Command} from "./command";
 import * as Common from "./common";
+import {Graph} from "../core/graph";
 import {loadGraph, type LoadGraphResult} from "../analysis/loadGraph";
 import {type IBackendAdapterLoader} from "../analysis/analysisAdapter";
+import {TimelineCred} from "../analysis/timeline/timelineCred";
+import {defaultWeights} from "../analysis/weights";
 
 import execDependencyGraph from "../tools/execDependencyGraph";
 import {loadGithubData} from "../plugins/github/loadGithubData";
 import {loadGitData} from "../plugins/git/loadGitData";
 import {defaultAdapterLoaders} from "./pagerank";
+import {DEFAULT_CRED_CONFIG} from "../plugins/defaultCredConfig";
 
 function usage(print: (string) => void): void {
   print(
@@ -170,7 +175,9 @@ export function makeLoadCommand(
 export type SaveGraph = (
   $ReadOnlyArray<IBackendAdapterLoader>,
   RepoId
-) => Promise<void>;
+) => Promise<Graph>;
+
+export type SaveCred = (Graph, RepoId) => Promise<void>;
 
 /**
  * A wrapper around the default plugin loader.
@@ -179,7 +186,10 @@ export type SaveGraph = (
  * (saveGraph depends on the directory state that's generated by running
  * load.)
  */
-export const makeLoadDefaultPlugins = (saveGraph: SaveGraph) => {
+export const makeLoadDefaultPlugins = (
+  saveGraph: SaveGraph,
+  saveCred: SaveCred
+) => {
   return async (options: LoadOptions) => {
     const sourcecredCommand = (args) => [
       process.execPath,
@@ -209,11 +219,39 @@ export const makeLoadDefaultPlugins = (saveGraph: SaveGraph) => {
       throw new Error("Load tasks failed.");
     }
     addToRepoIdRegistry(options.output);
-    await saveGraph(defaultAdapterLoaders(), options.output);
+    const graph = await saveGraph(defaultAdapterLoaders(), options.output);
+    await saveCred(graph, options.output);
     return;
   };
 };
 
+export const saveCred = async (graph: Graph, repoId: RepoId) => {
+  const id = "compute-cred";
+  console.time(id);
+  // Imitate the task labels from execDependencyGraph for visual consistency
+  console.log(chalk.bgBlue.bold.white("  GO  ") + ` ${id}`);
+  const cred = await TimelineCred.compute(
+    graph,
+    {
+      alpha: 0.05,
+      intervalDecay: 0.5,
+      weights: defaultWeights(),
+    },
+    DEFAULT_CRED_CONFIG
+  );
+  const credFile = path.join(
+    Common.sourcecredDirectory(),
+    "data",
+    repoIdToString(repoId),
+    "cred.json"
+  );
+  const credJSON = cred.toJSON();
+  await fs.writeFile(credFile, JSON.stringify(credJSON));
+  const badge = chalk.bgGreen.bold.white(" DONE ");
+  console.log(`${badge} ${id}`);
+  console.timeEnd(id);
+};
+
 export const loadIndividualPlugin = async (
   plugin: Common.PluginName,
   options: LoadOptions
@@ -266,7 +304,7 @@ function addToRepoIdRegistry(repoId) {
 export async function saveGraph(
   adapterLoaders: $ReadOnlyArray<IBackendAdapterLoader>,
   repoId: RepoId
-) {
+): Promise<Graph> {
   const loadGraphResult: LoadGraphResult = await loadGraph(
     Common.sourcecredDirectory(),
     adapterLoaders,
@@ -284,6 +322,7 @@ export async function saveGraph(
   );
   const graphJSON = graph.toJSON();
   await fs.writeFile(graphFile, stringify(graphJSON));
+  return graph;
 }
 
 export const help: Command = async (args, std) => {
@@ -296,7 +335,7 @@ export const help: Command = async (args, std) => {
   }
 };
 
-const loadDefaultPlugins = makeLoadDefaultPlugins(saveGraph);
+const loadDefaultPlugins = makeLoadDefaultPlugins(saveGraph, saveCred);
 const load = makeLoadCommand(loadIndividualPlugin, loadDefaultPlugins);
 
 export default load;

src/cli/load.test.js

@@ -3,6 +3,7 @@
 import path from "path";
 import tmp from "tmp";
 
+import {Graph} from "../core/graph";
 import {run} from "./testUtil";
 import {defaultPlugins} from "./common";
 import {
@@ -467,7 +468,7 @@ describe("cli/load", () => {
     const fooCombined = makeRepoId("foo", "combined");
     const fooBar = makeRepoId("foo", "bar");
     const fooBaz = makeRepoId("foo", "baz");
-    const loadDefaultPlugins = makeLoadDefaultPlugins(jest.fn());
+    const loadDefaultPlugins = makeLoadDefaultPlugins(jest.fn(), jest.fn());
 
     it("creates a load sub-task per plugin", async () => {
       execDependencyGraph.mockResolvedValue({success: true});
@@ -518,7 +519,7 @@ describe("cli/load", () => {
 
     it("calls saveGraph on success", async () => {
       const saveGraph = jest.fn();
-      const loadDefaultPlugins = makeLoadDefaultPlugins(saveGraph);
+      const loadDefaultPlugins = makeLoadDefaultPlugins(saveGraph, jest.fn());
       execDependencyGraph.mockResolvedValue({success: true});
       await loadDefaultPlugins({
         output: fooCombined,
@@ -531,6 +532,21 @@ describe("cli/load", () => {
       );
     });
 
+    it("calls saveCred with the output of saveGraph", async () => {
+      // $ExpectFlowError
+      const graph: Graph = "pretend_graph";
+      const saveGraph = jest.fn().mockResolvedValue(graph);
+      const saveCred = jest.fn();
+      const loadDefaultPlugins = makeLoadDefaultPlugins(saveGraph, saveCred);
+      execDependencyGraph.mockResolvedValue({success: true});
+      await loadDefaultPlugins({
+        output: fooCombined,
+        repoIds: [fooBar, fooBaz],
+      });
+      expect(saveCred).toHaveBeenCalledTimes(1);
+      expect(saveCred).toHaveBeenCalledWith(graph, fooCombined);
+    });
+
     it("throws an load error on first execDependencyGraph failure", async () => {
       execDependencyGraph.mockResolvedValueOnce({success: false});
       const result = loadDefaultPlugins({