WIP draft of a graphviz / mermaid generator

src/cli-options.ts

@@ -54,6 +54,7 @@ export interface Options {
   cache: 'local' | 'github' | 'none';
   failureMode: FailureMode;
   agent: Agent;
+  graph: boolean;
 }
 
 export const getOptions = (): Result<Options> => {
@@ -201,7 +202,7 @@ export const getOptions = (): Result<Options> => {
 function getArgvOptions(
   script: ScriptReference,
   agent: Agent
-): Pick<Options, 'watch' | 'extraArgs'> {
+): Pick<Options, 'watch' | 'extraArgs' | 'graph'> {
   // The way command-line arguments are handled in npm, yarn, and pnpm are all
   // different. Our goal here is for `<agent> --watch -- --extra` to behave the
   // same in all agents.
@@ -219,6 +220,7 @@ function getArgvOptions(
       return {
         watch: process.env['npm_config_watch'] !== undefined,
         extraArgs: process.argv.slice(2),
+        graph: true,
       };
     }
     case 'yarnClassic': {
@@ -355,7 +357,7 @@ function findRemainingArgsFromNpmConfigArgv(
  */
 function parseRemainingArgs(
   args: string[]
-): Pick<Options, 'watch' | 'extraArgs'> {
+): Pick<Options, 'watch' | 'extraArgs' | 'graph'> {
   let watch = false;
   let extraArgs: string[] = [];
   const unrecognized = [];
@@ -381,5 +383,6 @@ function parseRemainingArgs(
   return {
     watch,
     extraArgs,
+    graph: true,
   };
 }

src/cli.ts

@@ -92,6 +92,13 @@ const run = async (): Promise<Result<void, Failure[]>> => {
     if (!config.ok) {
       return config;
     }
+    if (options.graph) {
+      const {Graph} = await import('./graph.js');
+      const graph = new Graph(config.value);
+      await graph.generate();
+      return {ok: true, value: undefined};
+    }
+    console.log('\n\n\n\n\nOH NO!\n\n\n\n\n\n');
     const executor = new Executor(
       config.value,
       logger,

src/graph.ts

@@ -0,0 +1,88 @@
+import {ScriptConfig} from './config.js';
+import {relative} from 'path';
+
+interface Generator {
+  addEdge(from: string, to: string): void;
+  done(): void;
+}
+
+class GraphViz implements Generator {
+  constructor() {
+    console.log('digraph {');
+  }
+
+  addEdge(from: string, to: string) {
+    console.log(`  "${from}" -> "${to}";`);
+  }
+
+  done() {
+    console.log('}');
+  }
+}
+
+class Mermaid implements Generator {
+  #nextId = 0;
+  readonly #labelToId = new Map<string, number>();
+  constructor() {
+    console.log('graph TD');
+  }
+
+  addEdge(from: string, to: string) {
+    console.log(`  ${this.#format(from)} --> ${this.#format(to)}`);
+  }
+
+  #format(label: string) {
+    let id = this.#labelToId.get(label);
+    if (id === undefined) {
+      id = this.#nextId++;
+      this.#labelToId.set(label, id);
+      // TODO: properly escape the label
+      return `${id}[${label}]`;
+    }
+    return String(id);
+  }
+
+  done() {}
+}
+
+export class Graph {
+  readonly #config: ScriptConfig;
+  readonly #cwd = process.cwd();
+  readonly #generator: Generator;
+  constructor(config: ScriptConfig, kind: 'mermaid' | 'graphviz' = 'mermaid') {
+    this.#config = config;
+    if (kind === 'mermaid') {
+      this.#generator = new Mermaid();
+    } else {
+      this.#generator = new GraphViz();
+    }
+  }
+
+  generate() {
+    const seen = new Set<ScriptConfig>();
+    const queue = [this.#config];
+    let current;
+    while ((current = queue.pop())) {
+      if (seen.has(current)) {
+        continue;
+      }
+      seen.add(current);
+      for (const dependency of current.dependencies) {
+        this.#generator.addEdge(
+          this.#formatConfig(current),
+          this.#formatConfig(dependency.config)
+        );
+        queue.push(dependency.config);
+      }
+    }
+    this.#generator.done();
+  }
+
+  #formatConfig(config: ScriptConfig) {
+    const rel = relative(this.#cwd, config.packageDir);
+    if (rel === '') {
+      return config.name;
+    }
+    return `${rel}:${config.name}`;
+  }
+}