Unique File Tags

__tests__/testData/recursionStart/sub/dummyDoc.md

@@ -1,6 +1,7 @@
 # Dummy Doc
 
 This file dummyDoc.md is for unit tests in __tests__/ like e.g. fakeName.cpp or main.test.ts.
+The file main.ts shall be mentioned here and below.
 All tags that do not exist should contain 'fake' to help the unit tests.
 
 ## Related files and folders
@@ -9,3 +10,4 @@ All tags that do not exist should contain 'fake' to help the unit tests.
 - utils.ts
 - script/
 - __tests__/testData/taggedFolder/
+- script/

__tests__/utils.test.ts

@@ -3,10 +3,11 @@
  */
 
 import {
+  assertNonNull,
   getUrlToFile,
   getUrlToChanges,
   findFileByName,
-  assertNonNull
+  uniqueFilter
 } from '../src/utils'
 import * as github from '@actions/github'
 import { expect } from '@jest/globals'
@@ -132,4 +133,14 @@ describe('utils.ts context dependent', () => {
     // Calling the function with this context should throw an error.
     expect(() => getUrlToChanges(filePath)).toThrow()
   })
+
+  it('uniqueFilter(): Test functionality', () => {
+    const noDuplicates = [0, 1, 2, 3, 4]
+    const noDuplicatesFiltered = noDuplicates.filter(uniqueFilter)
+    expect(noDuplicatesFiltered).toEqual(noDuplicates)
+
+    const duplicates = [0, 1, 2, 2, 3, 4, 2]
+    const duplicatesFiltered = duplicates.filter(uniqueFilter)
+    expect(duplicatesFiltered).toEqual(noDuplicates)
+  })
 })

src/main.ts

@@ -6,12 +6,13 @@ import {
   assertNonNull,
   findFileByName,
   getUrlToChanges,
-  getUrlToFile
+  getUrlToFile,
+  uniqueFilter
 } from './utils'
 
 /**
  * Checks if file extensions start with a '.' and then only consist of letters and numbers.
- * @param extensions Array of extensions to check.
+ * @param extension The extensions to check.
  * @return True if extension matches the sane pattern.
  */
 function extensionsIsSane(extension: string): boolean {
@@ -35,7 +36,7 @@ function extractFileTags(
     .map(f => f.substring(1, f.length))
     .join('|')
   const srcFileRegex = new RegExp(`[^/\\s]+\\.(${extensionsCombined})\\b`, 'g')
-  return Array.from(fileContent.match(srcFileRegex) || [])
+  return Array.from(fileContent.match(srcFileRegex)?.filter(uniqueFilter) || [])
 }
 
 /**
@@ -53,7 +54,8 @@ function extractDirectoryTags(fileContent: string): string[] {
       // If there is nothing after the tag default to undefined and thus to []
       // Else match anything that ends on a '/'
       // \S = anything but whitespace
-      ?.match(/[\S]+\/(?!\S)/g) || []
+      ?.match(/[\S]+\/(?!\S)/g)
+      ?.filter(uniqueFilter) || []
   )
 }
 
@@ -94,7 +96,7 @@ function checkDocumentation(
     // Append the content of all directories to the tags.
     for (const tag of directoryTags) {
       if (!fs.existsSync(tag)) {
-        // If the dir can not be found it's an unknown tag.
+        // If the dir can not be found it's an unknown tag. Duplicates here are intentional.
         unknownTagsLocal.push(tag)
       } else {
         // Read the content of the directory and split it in files and dirs.
@@ -113,6 +115,9 @@ function checkDocumentation(
       }
     }
 
+    // Make sure all tags are only listed once
+    fileTags = fileTags.filter(uniqueFilter)
+
     // Analyze all file tags for doc changes.
     for (const tag of fileTags) {
       // If any tag appears in the changes, the doc file also has to be in the changes.

src/utils.ts

@@ -3,6 +3,20 @@ import * as path from 'path'
 import * as github from '@actions/github'
 import crypto from 'crypto'
 
+/**
+ * Filter function to remove duplicates in an array.
+ * @param value Value to check for duplication
+ * @param index Known index of first occurrence of value.
+ * @param container Array to filter.
+ */
+export function uniqueFilter<T>(
+  value: T,
+  index: number,
+  container: T[]
+): boolean {
+  return container.indexOf(value) === index
+}
+
 /**
  * Retrieves the value of an optional type.
  * If value is undefined or null an Error is thrown.