1 files changed, 153 insertions, 0 deletions
diff --git a/remote/test/puppeteer/tools/internal/job.ts b/remote/test/puppeteer/tools/internal/job.ts
new file mode 100644
index 0000000000..ef6ea10237
--- /dev/null
+++ b/remote/test/puppeteer/tools/internal/job.ts
@@ -0,0 +1,153 @@
+import {createHash} from 'crypto';
+import {existsSync, Stats} from 'fs';
+import {mkdir, readFile, stat, writeFile} from 'fs/promises';
+import {tmpdir} from 'os';
+import {dirname, join} from 'path';
+
+import glob from 'glob';
+
+interface JobContext {
+  name: string;
+  inputs: string[];
+  outputs: string[];
+}
+
+class JobBuilder {
+  #inputs: string[] = [];
+  #outputs: string[] = [];
+  #callback: (ctx: JobContext) => Promise<void>;
+  #name: string;
+  #value = '';
+  #force = false;
+
+  constructor(name: string, callback: (ctx: JobContext) => Promise<void>) {
+    this.#name = name;
+    this.#callback = callback;
+  }
+
+  get jobHash(): string {
+    return createHash('sha256').update(this.#name).digest('hex');
+  }
+
+  force() {
+    this.#force = true;
+    return this;
+  }
+
+  value(value: string) {
+    this.#value = value;
+    return this;
+  }
+
+  inputs(inputs: string[]): JobBuilder {
+    this.#inputs = inputs.flatMap(value => {
+      if (glob.hasMagic(value)) {
+        return glob.sync(value);
+      }
+      return value;
+    });
+    return this;
+  }
+
+  outputs(outputs: string[]): JobBuilder {
+    if (!this.#name) {
+      this.#name = outputs.join(' and ');
+    }
+
+    this.#outputs = outputs;
+    return this;
+  }
+
+  async build(): Promise<void> {
+    console.log(`Running job ${this.#name}...`);
+    // For debugging.
+    if (this.#force) {
+      return this.#run();
+    }
+    // In case we deleted an output file on purpose.
+    if (!this.getOutputStats()) {
+      return this.#run();
+    }
+    // Run if the job has a value, but it changes.
+    if (this.#value) {
+      if (!(await this.isValueDifferent())) {
+        return;
+      }
+      return this.#run();
+    }
+    // Always run when there is no output.
+    if (!this.#outputs.length) {
+      return this.#run();
+    }
+    // Make-like comparator.
+    if (!(await this.areInputsNewer())) {
+      return;
+    }
+    return this.#run();
+  }
+
+  async isValueDifferent(): Promise<boolean> {
+    const file = join(tmpdir(), `puppeteer/${this.jobHash}.txt`);
+    await mkdir(dirname(file), {recursive: true});
+    if (!existsSync(file)) {
+      await writeFile(file, this.#value);
+      return true;
+    }
+    return this.#value !== (await readFile(file, 'utf8'));
+  }
+
+  #outputStats?: Stats[];
+  async getOutputStats(): Promise<Stats[] | undefined> {
+    if (this.#outputStats) {
+      return this.#outputStats;
+    }
+    try {
+      this.#outputStats = await Promise.all(
+        this.#outputs.map(output => {
+          return stat(output);
+        })
+      );
+    } catch {}
+    return this.#outputStats;
+  }
+
+  async areInputsNewer(): Promise<boolean> {
+    const inputStats = await Promise.all(
+      this.#inputs.map(input => {
+        return stat(input);
+      })
+    );
+    const outputStats = await this.getOutputStats();
+    if (
+      outputStats &&
+      outputStats.reduce(reduceMinTime, Infinity) >
+        inputStats.reduce(reduceMaxTime, 0)
+    ) {
+      return false;
+    }
+    return true;
+  }
+
+  #run(): Promise<void> {
+    return this.#callback({
+      name: this.#name,
+      inputs: this.#inputs,
+      outputs: this.#outputs,
+    });
+  }
+}
+
+export const job = (
+  name: string,
+  callback: (ctx: JobContext) => Promise<void>
+): JobBuilder => {
+  return new JobBuilder(name, callback);
+};
+
+const reduceMaxTime = (time: number, stat: Stats) => {
+  return time < stat.mtimeMs ? stat.mtimeMs : time;
+};
+
+const reduceMinTime = (time: number, stat: Stats) => {
+  return time > stat.mtimeMs ? stat.mtimeMs : time;
+};