feat: creating compiling before hook

README.md

@@ -40,6 +40,25 @@ If `process.env.TS_NODE_BASEURL` is set it will override the value of `baseUrl`
 
 If `process.env.TS_NODE_PROJECT` is set it will be used to resolved tsconfig.json
 
+## With jest
+
+You can plug in tsconfig-paths as a before hook transformer for jest, just following the example below:
+
+```json
+"transform": {
+      "^.+\\.(t|j)s$": [
+        "ts-jest",
+        {
+          "astTransformers": {
+            "before": [
+              "node_modules/tsconfig-paths/plugin"
+            ]
+          }
+        }
+      ]
+    },
+```
+
 ### With webpack
 
 For webpack please use the [tsconfig-paths-webpack-plugin](https://github.com/dividab/tsconfig-paths-webpack-plugin).

package.json

@@ -7,6 +7,11 @@
   "author": "Jonas Kello",
   "license": "MIT",
   "repository": "https://github.com/dividab/tsconfig-paths",
+  "files": [
+    "lib",
+    "plugin.js",
+    "register.js"
+  ],
   "engines": {
     "node": ">=6"
   },

plugin.js

@@ -0,0 +1,3 @@
+// eslint-disable-next-line @typescript-eslint/no-require-imports
+module.exports = require('./lib/build-plugin/factory');
+module.exports.default = module.exports;

src/build-plugin/before-hook.ts

@@ -0,0 +1,111 @@
+/* eslint-disable @typescript-eslint/no-explicit-any */
+import * as os from "os";
+import { dirname, posix } from "path";
+import * as ts from "typescript";
+import { TypeScriptBinaryLoader } from "./typescript-loader";
+import { createMatchPath, MatchPath } from "../match-path-sync";
+import { tsConfigLoader } from "../tsconfig-loader";
+
+function getNotAliasedPath(
+  sf: ts.SourceFile,
+  matcher: MatchPath,
+  text: string
+): string | undefined {
+  let result = matcher(text, undefined, undefined, [
+    ".ts",
+    ".tsx",
+    ".js",
+    ".jsx",
+  ]);
+  if (!result) {
+    return;
+  }
+  if (os.platform() === "win32") {
+    result = result.replace(/\\/g, "/");
+  }
+  try {
+    // Installed packages (node modules) should take precedence over root files with the same name.
+    // Ref: https://github.com/nestjs/nest-cli/issues/838
+    const packagePath = require.resolve(text);
+    if (packagePath) {
+      return text;
+    }
+  } catch {
+    // ignore
+  }
+
+  const resolvedPath = posix.relative(dirname(sf.fileName), result) || "./";
+  return resolvedPath.startsWith(".") ? resolvedPath : "./" + resolvedPath;
+}
+
+const compilerOptions = tsConfigLoader({
+  cwd: process.cwd(),
+  getEnv: (key: string) => process.env[key],
+});
+
+export function tsconfigPathsBeforeHookFactory(): (
+  ctx: ts.TransformationContext
+) => ts.Transformer<ts.Node> {
+  const tsBinary = new TypeScriptBinaryLoader().load();
+  const { paths = {}, baseUrl = "./" } = compilerOptions;
+  const matcher = createMatchPath(baseUrl, paths, ["main"]);
+
+  return (ctx: ts.TransformationContext): ts.Transformer<ts.Node> => {
+    return (sf: ts.SourceFile) => {
+      const visitNode = (node: ts.Node): ts.Node => {
+        if (
+          tsBinary.isImportDeclaration(node) ||
+          (tsBinary.isExportDeclaration(node) && node.moduleSpecifier)
+        ) {
+          try {
+            const importPathWithQuotes = node.moduleSpecifier?.getText();
+
+            if (!importPathWithQuotes) {
+              return node;
+            }
+            const text = importPathWithQuotes.substring(
+              1,
+              importPathWithQuotes.length - 1
+            );
+            const result = getNotAliasedPath(sf, matcher, text);
+            if (!result) {
+              return node;
+            }
+            const moduleSpecifier =
+              tsBinary.factory.createStringLiteral(result);
+            (moduleSpecifier as any).parent = (
+              node as any
+            ).moduleSpecifier.parent;
+
+            if (tsBinary.isImportDeclaration(node)) {
+              const updatedNode = tsBinary.factory.updateImportDeclaration(
+                node,
+                node.modifiers,
+                node.importClause,
+                moduleSpecifier,
+                node.assertClause
+              );
+              (updatedNode as any).flags = node.flags;
+              return updatedNode;
+            } else {
+              const updatedNode = tsBinary.factory.updateExportDeclaration(
+                node,
+                node.modifiers,
+                node.isTypeOnly,
+                node.exportClause,
+                moduleSpecifier,
+                node.assertClause
+              );
+              (updatedNode as any).flags = node.flags;
+              return updatedNode;
+            }
+          } catch {
+            return node;
+          }
+        }
+        return tsBinary.visitEachChild(node, visitNode, ctx);
+      };
+      return tsBinary.visitNode(sf, visitNode);
+    };
+  };
+}

src/build-plugin/factory.ts

@@ -0,0 +1,5 @@
+import { tsconfigPathsBeforeHookFactory } from "./before-hook";
+
+export const name = "tsconfig-paths";
+export const version = 1;
+export const factory = tsconfigPathsBeforeHookFactory;

src/build-plugin/typescript-loader.ts

@@ -0,0 +1,24 @@
+/* eslint-disable no-magic-numbers */
+import * as ts from "typescript";
+
+export class TypeScriptBinaryLoader {
+  private tsBinary?: typeof ts;
+
+  public load(): typeof ts {
+    if (this.tsBinary) {
+      return this.tsBinary;
+    }
+
+    try {
+      const tsBinaryPath = require.resolve("typescript");
+      // eslint-disable-next-line @typescript-eslint/no-var-requires, @typescript-eslint/no-require-imports
+      const tsBinary = require(tsBinaryPath);
+      this.tsBinary = tsBinary;
+      return tsBinary;
+    } catch {
+      throw new Error(
+        'TypeScript could not be found! Please, install "typescript" package.'
+      );
+    }
+  }
+}