Add --preprocessor argument + support multiple reporters (resolves #204)

README.md

@@ -645,7 +645,8 @@ for false positives, and how to handle them.
       --exports                Shortcut for --include exports,nsExports,classMembers,types,nsTypes,enumMembers,duplicates
       --include-entry-exports  Include entry files when reporting unused exports
       -n, --no-progress        Don't show dynamic progress updates (automatically enabled in CI environments)
-      --reporter               Select reporter: symbols, compact, codeowners, json (default: symbols)
+      --preprocessor           Preprocess the results before providing it to the reporter(s), can be repeated
+      --reporter               Select reporter: symbols, compact, codeowners, json, can be repeated (default: symbols)
       --reporter-options       Pass extra options to the reporter (as JSON string, see example)
       --no-config-hints        Suppress configuration hints
       --no-exit-code           Always exit with code zero (0)

fixtures/preprocessors/identity.ts

@@ -0,0 +1,5 @@
+import { ReporterOptions } from '../../src/types/issues';
+
+export default function identity(value: ReporterOptions): ReporterOptions {
+  return value;
+}

fixtures/preprocessors/minimal.ts

@@ -0,0 +1,11 @@
+import { Preprocessor } from '../../src/types/issues';
+
+const minimal: Preprocessor = value => ({
+  ...value,
+  issues: {
+    ...value.issues,
+    files: new Set([...value.issues.files, import.meta.url]),
+  },
+});
+
+export default minimal;

fixtures/reporters/minimal.ts

@@ -0,0 +1,17 @@
+import type { ReporterOptions, IssueSet, IssueRecords } from '../../src/types/issues.js';
+import type { Entries } from 'type-fest';
+
+export default ({ report, issues }: ReporterOptions) => {
+  for (const [reportType, isReportType] of Object.entries(report) as Entries<typeof report>) {
+    if (isReportType) {
+      const isSet = issues[reportType] instanceof Set;
+      const issuesForType = isSet
+        ? Array.from(issues[reportType] as IssueSet)
+        : reportType === 'duplicates'
+        ? Object.values(issues[reportType]).map(Object.values).flat()
+        : Object.values(issues[reportType] as IssueRecords);
+
+      console.log(reportType, issuesForType.length);
+    }
+  }
+};

src/cli.ts

@@ -2,15 +2,15 @@
 
 import './util/register.js';
 import prettyMilliseconds from 'pretty-ms';
-import reporters from './reporters/index.js';
+import internalReporters from './reporters/index.js';
 import parsedArgValues, { helpText } from './util/cli-arguments.js';
 import { isKnownError, getKnownError, isConfigurationError, hasCause } from './util/errors.js';
 import { _load } from './util/loader.js';
 import { cwd, resolve } from './util/path.js';
 import { Performance } from './util/Performance.js';
 import { version } from './version.js';
 import { main } from './index.js';
-import type { IssueType } from './types/issues.js';
+import type { ReporterOptions, IssueType } from './types/issues.js';
 
 const {
   debug: isDebug = false,
@@ -24,7 +24,8 @@ const {
   'include-entry-exports': isIncludeEntryExports = false,
   performance: isObservePerf = false,
   production: isProduction = false,
-  reporter = 'symbols',
+  preprocessor = [],
+  reporter = ['symbols'],
   'reporter-options': reporterOptions = '',
   strict: isStrict = false,
   tsConfig,
@@ -44,8 +45,18 @@ if (isVersion) {
 const isShowProgress =
   !isDebug && isNoProgress === false && process.stdout.isTTY && typeof process.stdout.cursorTo === 'function';
 
-const printReport =
-  reporter in reporters ? reporters[reporter as keyof typeof reporters] : await _load(resolve(reporter));
+const preprocessors = await Promise.all(preprocessor.map(processor => _load(resolve(processor))));
+
+const processAsync = (data: ReporterOptions, processors: typeof preprocessors): Promise<ReporterOptions> =>
+  processors.length === 0 ? Promise.resolve(data) : processAsync(processors[0](data), processors.slice(1));
+
+const reporters = await Promise.all(
+  reporter.map(async reporter => {
+    return reporter in internalReporters
+      ? internalReporters[reporter as keyof typeof internalReporters]
+      : await _load(resolve(reporter));
+  })
+);
 
 const run = async () => {
   try {
@@ -62,7 +73,7 @@ const run = async () => {
       isIncludeEntryExports,
     });
 
-    await printReport({
+    const initialData: ReporterOptions = {
       report,
       issues,
       configurationHints,
@@ -71,7 +82,11 @@ const run = async () => {
       isProduction,
       isShowProgress,
       options: reporterOptions,
-    });
+    };
+
+    const finalData = await processAsync(initialData, preprocessors);
+
+    for (const reporter of reporters) await reporter(finalData);
 
     const totalErrorCount = (Object.keys(report) as IssueType[])
       .filter(reportGroup => report[reportGroup] && rules[reportGroup] === 'error')

src/index.ts

@@ -36,7 +36,7 @@ type HandleReferencedDependencyOptions = {
 };
 
 export type { RawConfiguration as KnipConfig } from './types/config.js';
-export type { Reporter, ReporterOptions } from './types/issues.js';
+export type { Preprocessor, Reporter, ReporterOptions } from './types/issues.js';
 
 export const main = async (unresolvedConfiguration: CommandLineOptions) => {
   const {

src/types/issues.ts

@@ -54,14 +54,15 @@ export type ReporterOptions = {
   configurationHints: ConfigurationHints;
   noConfigHints: boolean;
   cwd: string;
-  workingDir: string;
   isProduction: boolean;
   isShowProgress: boolean;
   options: string;
 };
 
 export type Reporter = (options: ReporterOptions) => void;
 
+export type Preprocessor = (options: ReporterOptions) => ReporterOptions;
+
 export type IssueSeverity = 'error' | 'warn' | 'off';
 
 export type Rules = Record<IssueType, IssueSeverity>;

src/util/cli-arguments.ts

@@ -18,7 +18,8 @@ Options:
   --exports                Shortcut for --include exports,nsExports,classMembers,types,nsTypes,enumMembers,duplicates
   --include-entry-exports  Include entry files when reporting unused exports
   -n, --no-progress        Don't show dynamic progress updates (automatically enabled in CI environments)
-  --reporter               Select reporter: symbols, compact, codeowners, json (default: symbols)
+  --preprocessor           Preprocess the results before providing it to the reporter(s), can be repeated
+  --reporter               Select reporter: symbols, compact, codeowners, json, can be repeated (default: symbols)
   --reporter-options       Pass extra options to the reporter (as JSON string, see example)
   --no-config-hints        Suppress configuration hints
   --no-exit-code           Always exit with code zero (0)
@@ -63,7 +64,8 @@ try {
       'no-progress': { type: 'boolean', short: 'n' },
       performance: { type: 'boolean' },
       production: { type: 'boolean' },
-      reporter: { type: 'string' },
+      preprocessor: { type: 'string', multiple: true },
+      reporter: { type: 'string', multiple: true },
       'reporter-options': { type: 'string' },
       strict: { type: 'boolean' },
       tsConfig: { type: 'string', short: 't' },