From 2bcb7a7b7311feca3d52ac5b163c8f5c6bd3caad Mon Sep 17 00:00:00 2001
From: Mark Brouch <mark.brouch@gmail.com>
Date: Thu, 19 Dec 2019 17:19:59 -0600
Subject: [PATCH] =?UTF-8?q?=E2=9C=A8=20Create=20generate=20todo?=
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---
 src/index.ts     | 33 +++++++++++++++++++++++++++++++++
 src/overrides.ts | 33 +++++++++++++++++++++++++++++++++
 src/render.ts    | 23 +++++++++++++++++++++++
 3 files changed, 89 insertions(+)
 create mode 100644 src/index.ts
 create mode 100644 src/overrides.ts
 create mode 100644 src/render.ts

diff --git a/src/index.ts b/src/index.ts
new file mode 100644
index 0000000..336949f
--- /dev/null
+++ b/src/index.ts
@@ -0,0 +1,33 @@
+import fs from "fs";
+import util from "util";
+import { CLIEngine, Linter } from "eslint";
+
+import { renderAsYAML, renderAsJSON } from "./render";
+import { mapReportToOverrides } from "./overrides";
+
+const writeFile = util.promisify(fs.writeFile);
+
+export async function execute(
+  files: Array<string>,
+  {
+    level,
+    format = "yaml",
+    path
+  }: { level: Linter.RuleLevel; format: "yaml" | "json"; path?: string }
+): Promise<string> {
+  const cli = new CLIEngine({});
+
+  const report = cli.executeOnFiles(files) as CLIEngine.LintReport;
+  const config = { overrides: mapReportToOverrides(report, level) };
+
+  const outputPath =
+    path || `.eslintrc-todo.${format === "yaml" ? "yml" : "json"}`;
+
+  await writeFile(
+    outputPath,
+    format === "yaml" ? renderAsYAML(config) : renderAsJSON(config),
+    { encoding: "utf8" }
+  );
+
+  return outputPath;
+}
diff --git a/src/overrides.ts b/src/overrides.ts
new file mode 100644
index 0000000..1f44e75
--- /dev/null
+++ b/src/overrides.ts
@@ -0,0 +1,33 @@
+import path from "path";
+import { CLIEngine, Linter } from "eslint";
+
+function stripEmptyFiles(
+  results: CLIEngine.LintResult[]
+): CLIEngine.LintResult[] {
+  return results.filter(result => !!result.messages.length);
+}
+
+function stripNullRuleIds(ruleIds: (string | null)[]): string[] {
+  return ruleIds.filter((ruleId): ruleId is string => ruleId !== null);
+}
+
+export function mapReportToOverrides(
+  report: CLIEngine.LintReport,
+  level: Linter.RuleLevel
+): Linter.RuleOverride[] {
+  return stripEmptyFiles(report.results).map((result: CLIEngine.LintResult) => {
+    const uniqueRuleIds = Array.from(
+      new Set(result.messages.map(message => message.ruleId))
+    );
+
+    const rules: Linter.RulesRecord = {};
+    stripNullRuleIds(uniqueRuleIds).forEach(ruleId => {
+      rules[ruleId] = level;
+    });
+
+    return {
+      files: [path.relative(process.cwd(), result.filePath)],
+      rules
+    };
+  });
+}
diff --git a/src/render.ts b/src/render.ts
new file mode 100644
index 0000000..f42da18
--- /dev/null
+++ b/src/render.ts
@@ -0,0 +1,23 @@
+import { Linter } from "eslint";
+import yaml from "js-yaml";
+
+function generateYAMLCommentBlock(): string {
+  return `# This configuration was generated by
+# \`eslint-generate-todo\` (http://github.com/doximity/eslint-generate-todo)
+#
+# on ${new Date().toISOString()}.
+#
+# It contains all the known ESLint errors/warnings, and prevents them from
+# showing up as errors until devs can remove them from the code base.
+# Regenerate this file as errors are fixed.
+
+`;
+}
+
+export function renderAsYAML(config: Linter.Config): string {
+  return `${generateYAMLCommentBlock()}${yaml.dump(config)}`;
+}
+
+export function renderAsJSON(config: Linter.Config): string {
+  return JSON.stringify(config, null, 2);
+}