Add a script for updationg the links

Author: orta

.gitignore

@@ -102,4 +102,7 @@ dist
 
 # TernJS port file
 .tern-port
-.DS_Store
+.DS_Store
+
+yarn.lock
+package-lock.json

package.json

@@ -0,0 +1,12 @@
+{
+    "dependencies": {
+      "markdown-magic": "^1.0.0",
+      "typescript": "latest",
+      "glob": "^7.1.6",
+      "escape-regex-string": "^1.0.6"
+    },
+    "scripts": {
+      "update": "node scripts/convertRelativeLinksToHardcoded.js **/*.md"
+    }
+  }
+  

scripts/updateFindLinks.js

@@ -0,0 +1,125 @@
+// @ts-check
+
+// Loop through all files switching a reference like:
+//
+//  [13]: <src/compiler/checker.ts - function checkIfStatement>
+//
+// to
+//
+//  [13]: https://github.com/microsoft/TypeScript/blob/8d986554/src/compiler/checker.ts#L30308
+//  [13]: <src/compiler/checker.ts - function checkIfStatement>
+// 
+// GitHub uses the first link and ignores the 2nd. If the dupe is already there,
+// then it updates to a new url.
+
+// Validate:
+// node scripts/updateFindLinks.js scripts/fixtures/input.md
+
+// Write:
+// node scripts/updateFindLinks.js scripts/fixtures/input.md --write
+
+const glob = require("glob");
+const { readFileSync, writeFileSync, existsSync } = require("fs");
+const { join } = require("path");
+const { execSync } = require("child_process");
+const escapeRegex = require("escape-regex-string");
+
+if (!process.argv[2]) throw new Error("Did not include a glob for markdown files to change");
+
+// This can be anything
+const write = process.argv[3] !== undefined;
+
+const possibleTSRepo = ["../typescript-compiler", "../TypeScript", "TypeScript"];
+let repoPath = possibleTSRepo.find(f => existsSync(join(f, "package.json")));
+if (!repoPath) throw new Error("Could not find a TypeScript repo");
+
+const repoHead = execSync(`git rev-parse HEAD | cut -c 1-8`, { cwd: repoPath, encoding: "utf8" });
+if (!repoHead) throw new Error("Could not get the git info from the sibling TypeScript repo");
+
+const files = glob.sync(process.argv[2]);
+if (!files.length) throw new Error("Did not get any files with that glob");
+
+let failed = [];
+
+files.forEach(file => {
+  if (file === "README.md") return;
+
+  let content = readFileSync(file, "utf8");
+  // https://regex101.com/r/w1dEG1/1
+  const regex = new RegExp(/\[.*]: <(.*) - (.*)>/g);
+
+  const matches = content.matchAll(regex)
+  for (const result of matches) {
+    const fileRef = result[1];
+    const searchTerm = result[2];
+    const original = `: <${fileRef} - ${searchTerm}>`;
+    const originalLine = getLineOfStr(content, original)[0].number
+    const reference = lineOfStr(content, originalLine-1).slice(1).split("]")[0]
+    const lineToChange = lineOfStr(content, originalLine-2)
+    const shouldReplace = lineToChange.includes("/blob/")
+    try {
+      const originalFile = readFileSync(join(repoPath, fileRef), "utf8");
+      const line = getLineNo(originalFile, new RegExp(escapeRegex(searchTerm)));
+      const lineRef = line && line[0] && line[0].number ? `#L${line[0].number}` : "";
+      const replacement = `[${reference}]: https://github.com/microsoft/TypeScript/blob/${repoHead.trim()}/${fileRef}${lineRef}`;
+      content = content.replace(lineToChange, shouldReplace ? replacement : lineToChange + "\n" + replacement);
+    } catch (e) {
+      console.log(e)
+      failed.push([file, fileRef]);
+    }
+  }
+
+  if (write) {
+    writeFileSync(file, content);
+  } else {
+    console.log(content);
+  }
+});
+
+if (failed.length) {
+  console.error("Could not find the following references to update:");
+  console.error(failed);
+
+  console.error("Either ping @orta if confused about this failure, or update the filepaths please. It's likely they've moved in the TypeScript repo.");
+  process.exit(1);
+}
+
+function lineOfStr(str, idx) {
+  return str.split(/\r?\n/)[idx]
+}
+
+function getLineOfStr(str, substr) {
+  return str
+    .split(/\r?\n/)
+    .map(function(line, i) {
+      if (line.includes(substr)) {
+        return {
+          number: i + 1,
+          line
+        };
+      }
+    })
+    .filter(Boolean);
+}
+
+
+/*!
+ * line-number <https://github.com/jonschlinkert/line-number>
+ *
+ * Copyright (c) 2014 Jon Schlinkert, contributors.
+ * Licensed under the MIT License
+ */
+function getLineNo(str, re) {
+  return str
+    .split(/\r?\n/)
+    .map(function(line, i) {
+      if (re.test(line)) {
+        return {
+          line: line,
+          number: i + 1,
+          match: line.match(re)[0]
+        };
+      }
+    })
+    .filter(Boolean);
+}