💯 Test overrides

src/__tests__/overrides.spec.ts

@@ -0,0 +1,112 @@
+import { CLIEngine } from "eslint";
+
+import {
+  stripEmptyFiles,
+  stripNullRuleIds,
+  mapReportToOverrides
+} from "../overrides";
+
+function generateLintResult(ruleIds: string[] = []): CLIEngine.LintResult {
+  return {
+    filePath: "foo",
+    messages: ruleIds.map(ruleId => ({
+      column: 0,
+      line: 0,
+      ruleId,
+      message: "",
+      nodeType: "",
+      severity: 0,
+      source: ""
+    })),
+    errorCount: 0,
+    warningCount: 0,
+    fixableErrorCount: 0,
+    fixableWarningCount: 0
+  };
+}
+
+function generateReport(
+  results: CLIEngine.LintResult[] = []
+): CLIEngine.LintReport {
+  return {
+    results,
+    errorCount: 0,
+    warningCount: 0,
+    fixableErrorCount: 0,
+    fixableWarningCount: 0
+  };
+}
+
+describe("stripEmptyFiles", () => {
+  test("removes results with no messages", () => {
+    const results = [
+      generateLintResult(),
+      generateLintResult(["foo", "bar"]),
+      generateLintResult()
+    ];
+
+    expect(stripEmptyFiles(results)).toEqual([results[1]]);
+  });
+});
+
+describe("stripNullRuleIds", () => {
+  test("removes null rule IDs", () => {
+    const ruleIds = ["foo", null, "bar", null, "baz"];
+
+    expect(stripNullRuleIds(ruleIds)).toEqual(["foo", "bar", "baz"]);
+  });
+});
+
+describe("mapReportToOverrides", () => {
+  test("creates a list of overrides from a report", () => {
+    const report = generateReport([generateLintResult(["foo", "bar"])]);
+
+    expect(mapReportToOverrides(report, "warn")).toEqual([
+      {
+        files: ["foo"],
+        rules: {
+          foo: "warn",
+          bar: "warn"
+        }
+      }
+    ]);
+  });
+
+  test("sets the level of the rules", () => {
+    const report = generateReport([generateLintResult(["foo", "bar"])]);
+
+    expect(mapReportToOverrides(report, "warn")).toEqual([
+      {
+        files: ["foo"],
+        rules: {
+          foo: "warn",
+          bar: "warn"
+        }
+      }
+    ]);
+
+    expect(mapReportToOverrides(report, "off")).toEqual([
+      {
+        files: ["foo"],
+        rules: {
+          foo: "off",
+          bar: "off"
+        }
+      }
+    ]);
+  });
+
+  test("combines duplicate rule violations", () => {
+    const report = generateReport([generateLintResult(["foo", "foo", "bar"])]);
+
+    expect(mapReportToOverrides(report, "warn")).toEqual([
+      {
+        files: ["foo"],
+        rules: {
+          foo: "warn",
+          bar: "warn"
+        }
+      }
+    ]);
+  });
+});

src/overrides.ts

@@ -1,13 +1,13 @@
 import path from "path";
 import { CLIEngine, Linter } from "eslint";
 
-function stripEmptyFiles(
+export function stripEmptyFiles(
   results: CLIEngine.LintResult[]
 ): CLIEngine.LintResult[] {
   return results.filter(result => !!result.messages.length);
 }
 
-function stripNullRuleIds(ruleIds: (string | null)[]): string[] {
+export function stripNullRuleIds(ruleIds: (string | null)[]): string[] {
   return ruleIds.filter((ruleId): ruleId is string => ruleId !== null);
 }