Introduce createFilenameFromString function

extensions/ql-vscode/src/common/filenames.ts

@@ -0,0 +1,43 @@
+type FilenameOptions = {
+  removeDots?: boolean;
+};
+
+/**
+ * This will create a filename from an arbitrary string by removing
+ * all characters which are not allowed in filenames and making them
+ * more filesystem-friendly be replacing undesirable characters with
+ * hyphens. The result will always be lowercase ASCII.
+ *
+ * @param str The string to create a filename from
+ * @param removeDots Whether to remove dots from the filename [default: false]
+ * @returns The filename
+ */
+export function createFilenameFromString(
+  str: string,
+  { removeDots }: FilenameOptions = {},
+) {
+  let fileName = str;
+
+  // Lowercase everything
+  fileName = fileName.toLowerCase();
+
+  // Replace all spaces, underscores, slashes, and backslashes with hyphens
+  fileName = fileName.replaceAll(/[\s_/\\]+/g, "-");
+
+  // Replace all characters which are not allowed by empty strings
+  fileName = fileName.replaceAll(/[^a-z0-9.-]/g, "");
+
+  // Remove any leading or trailing hyphens or dots
+  fileName = fileName.replaceAll(/^[.-]+|[.-]+$/g, "");
+
+  // Remove any duplicate hyphens
+  fileName = fileName.replaceAll(/-{2,}/g, "-");
+  // Remove any duplicate dots
+  fileName = fileName.replaceAll(/\.{2,}/g, ".");
+
+  if (removeDots) {
+    fileName = fileName.replaceAll(/\./g, "-");
+  }
+
+  return fileName;
+}

extensions/ql-vscode/src/databases/database-fetcher.ts

@@ -40,6 +40,7 @@ import { getLanguageDisplayName } from "../common/query-language";
 import type { DatabaseOrigin } from "./local-databases/database-origin";
 import { createTimeoutSignal } from "../common/fetch-stream";
 import type { App } from "../common/app";
+import { createFilenameFromString } from "../common/filenames";
 
 /**
  * Prompts a user to fetch a database from a remote location. Database is assumed to be an archive file.
@@ -421,22 +422,7 @@ async function getStorageFolder(
   let lastName: string;
 
   if (nameOverrride) {
-    // Lowercase everything
-    let name = nameOverrride.toLowerCase();
-
-    // Replace all spaces, dots, underscores, and forward slashes with hyphens
-    name = name.replaceAll(/[\s._/]+/g, "-");
-
-    // Replace all characters which are not allowed by empty strings
-    name = name.replaceAll(/[^a-z0-9-]/g, "");
-
-    // Remove any leading or trailing hyphens
-    name = name.replaceAll(/^-|-$/g, "");
-
-    // Remove any duplicate hyphens
-    name = name.replaceAll(/-{2,}/g, "-");
-
-    lastName = name;
+    lastName = createFilenameFromString(nameOverrride);
   } else {
     // we need to generate a folder name for the unzipped archive,
     // this needs to be human readable since we may use this name as the initial

extensions/ql-vscode/src/model-editor/extension-pack-name.ts

@@ -1,3 +1,5 @@
+import { createFilenameFromString } from "../common/filenames";
+
 const packNamePartRegex = /[a-z0-9](?:[a-z0-9-]*[a-z0-9])?/;
 const packNameRegex = new RegExp(
   `^(?<scope>${packNamePartRegex.source})/(?<name>${packNamePartRegex.source})$`,
@@ -23,7 +25,11 @@ export function autoNameExtensionPack(
   }
 
   const parts = packName.split("/");
-  const sanitizedParts = parts.map((part) => sanitizeExtensionPackName(part));
+  const sanitizedParts = parts.map((part) =>
+    createFilenameFromString(part, {
+      removeDots: true,
+    }),
+  );
 
   // If the scope is empty (e.g. if the given name is "-/b"), then we need to still set a scope
   if (sanitizedParts[0].length === 0) {
@@ -37,25 +43,6 @@ export function autoNameExtensionPack(
   };
 }
 
-function sanitizeExtensionPackName(name: string) {
-  // Lowercase everything
-  name = name.toLowerCase();
-
-  // Replace all spaces, dots, and underscores with hyphens
-  name = name.replaceAll(/[\s._]+/g, "-");
-
-  // Replace all characters which are not allowed by empty strings
-  name = name.replaceAll(/[^a-z0-9-]/g, "");
-
-  // Remove any leading or trailing hyphens
-  name = name.replaceAll(/^-|-$/g, "");
-
-  // Remove any duplicate hyphens
-  name = name.replaceAll(/-{2,}/g, "-");
-
-  return name;
-}
-
 export function parsePackName(packName: string): ExtensionPackName | undefined {
   const matches = packNameRegex.exec(packName);
   if (!matches?.groups) {

extensions/ql-vscode/src/model-editor/yaml.ts

@@ -20,6 +20,7 @@ import type {
   ModelExtension,
   ModelExtensionFile,
 } from "./model-extension-file";
+import { createFilenameFromString } from "../common/filenames";
 import type { QueryLanguage } from "../common/query-language";
 
 import modelExtensionFileSchema from "./model-extension-file.schema.json";
@@ -275,26 +276,7 @@ export function createFilenameForLibrary(
   prefix = "models/",
   suffix = ".model",
 ) {
-  let libraryName = library;
-
-  // Lowercase everything
-  libraryName = libraryName.toLowerCase();
-
-  // Replace all spaces and underscores with hyphens
-  libraryName = libraryName.replaceAll(/[\s_]+/g, "-");
-
-  // Replace all characters which are not allowed by empty strings
-  libraryName = libraryName.replaceAll(/[^a-z0-9.-]/g, "");
-
-  // Remove any leading or trailing hyphens or dots
-  libraryName = libraryName.replaceAll(/^[.-]+|[.-]+$/g, "");
-
-  // Remove any duplicate hyphens
-  libraryName = libraryName.replaceAll(/-{2,}/g, "-");
-  // Remove any duplicate dots
-  libraryName = libraryName.replaceAll(/\.{2,}/g, ".");
-
-  return `${prefix}${libraryName}${suffix}.yml`;
+  return `${prefix}${createFilenameFromString(library)}${suffix}.yml`;
 }
 
 export function createFilenameForPackage(

extensions/ql-vscode/test/unit-tests/common/filenames.test.ts

@@ -0,0 +1,80 @@
+import { createFilenameFromString } from "../../../src/common/filenames";
+
+describe("createFilenameFromString", () => {
+  const testCases: Array<{
+    input: string;
+    filename: string;
+    filenameWithoutDots?: string;
+  }> = [
+    {
+      input: "sql2o",
+      filename: "sql2o",
+    },
+    {
+      input: "spring-boot",
+      filename: "spring-boot",
+    },
+    {
+      input: "spring--boot",
+      filename: "spring-boot",
+    },
+    {
+      input: "rt",
+      filename: "rt",
+    },
+    {
+      input: "System.Runtime",
+      filename: "system.runtime",
+      filenameWithoutDots: "system-runtime",
+    },
+    {
+      input: "System..Runtime",
+      filename: "system.runtime",
+      filenameWithoutDots: "system-runtime",
+    },
+    {
+      input: "google/brotli",
+      filename: "google-brotli",
+    },
+    {
+      input: "github/vscode-codeql",
+      filename: "github-vscode-codeql",
+    },
+    {
+      input: "github/vscode---codeql--",
+      filename: "github-vscode-codeql",
+    },
+    {
+      input: "github...vscode--c..odeql",
+      filename: "github.vscode-c.odeql",
+      filenameWithoutDots: "github-vscode-c-odeql",
+    },
+    {
+      input: "github\\vscode-codeql",
+      filename: "github-vscode-codeql",
+    },
+    {
+      input: "uNetworking/uWebSockets.js",
+      filename: "unetworking-uwebsockets.js",
+      filenameWithoutDots: "unetworking-uwebsockets-js",
+    },
+  ];
+
+  test.each(testCases)(
+    "returns $filename if string is $input",
+    ({ input, filename }) => {
+      expect(createFilenameFromString(input)).toEqual(filename);
+    },
+  );
+
+  test.each(testCases)(
+    "returns $filename if string is $input and dots are not allowed",
+    ({ input, filename, filenameWithoutDots }) => {
+      expect(
+        createFilenameFromString(input, {
+          removeDots: true,
+        }),
+      ).toEqual(filenameWithoutDots ?? filename);
+    },
+  );
+});