fix: compiler crashes when a contract name exceeds filesystem limits

dev-docs/CHANGELOG.md

@@ -11,6 +11,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - [fix] Disallow self-inheritance for contracts and traits: PR [#3094](https://github.com/tact-lang/tact/pull/3094)
 - [fix] Added fixed-bytes support to bounced message size calculations: PR [#3129](https://github.com/tact-lang/tact/pull/3129)
+- [fix] Fixed compiler crashes when a contract name exceeds filesystem limits: PR [#3219](https://github.com/tact-lang/tact/pull/3219)
 - Compiler now generates more efficient code for serialization: PR [#3213](https://github.com/tact-lang/tact/pull/3213)
 - [fix] Compiler now doesn't generate `__tact_nop()` for `dump()` and `dumpStack()` in default mode: PR [#3218](https://github.com/tact-lang/tact/pull/3218)
 

src/vfs/createNodeFileSystem.spec.ts

@@ -1,6 +1,7 @@
 import path from "path";
 import fs from "fs";
 import { createNodeFileSystem } from "@/vfs/createNodeFileSystem";
+import { makeSafeName } from "@/vfs/utils";
 
 describe("createNodeFileSystem", () => {
     it("should open file system", () => {
@@ -46,4 +47,72 @@ describe("createNodeFileSystem", () => {
             fs.rmSync(realPathDir2, { recursive: true, force: true });
         }
     });
+
+    it("should truncate and hash long filenames", () => {
+        const baseDir = path.resolve(__dirname, "./__testdata");
+        const vfs = createNodeFileSystem(baseDir, false);
+
+        const longName = "A".repeat(300);
+        const content = "Test content";
+        const ext = ".md";
+
+        const inputPath = vfs.resolve(`${longName}${ext}`);
+        const dir = path.dirname(inputPath);
+        const expectedSafeName = makeSafeName(longName, ext);
+        const expectedFullPath = path.join(dir, expectedSafeName);
+
+        try {
+            if (fs.existsSync(expectedFullPath)) {
+                fs.unlinkSync(expectedFullPath);
+            }
+
+            vfs.writeFile(inputPath, content);
+            expect(fs.existsSync(expectedFullPath)).toBe(true);
+
+            const actualContent = fs.readFileSync(expectedFullPath, "utf8");
+            expect(actualContent).toBe(content);
+
+            expect(expectedSafeName.length).toBeLessThanOrEqual(255);
+            expect(expectedSafeName).toMatch(
+                new RegExp(
+                    `^${longName.slice(0, 255 - ext.length - 9)}_[0-9a-f]{8}${ext}$`,
+                ),
+            );
+        } finally {
+            if (fs.existsSync(expectedFullPath)) {
+                fs.unlinkSync(expectedFullPath);
+            }
+        }
+    });
+    it("should not truncate or hash short filenames", () => {
+        const baseDir = path.resolve(__dirname, "./__testdata");
+        const vfs = createNodeFileSystem(baseDir, false);
+
+        const shortName = "short-filename";
+        const content = "Test content";
+        const ext = ".md";
+
+        const inputPath = vfs.resolve(`${shortName}${ext}`);
+        const dir = path.dirname(inputPath);
+        const expectedSafeName = makeSafeName(shortName, ext);
+        const expectedFullPath = path.join(dir, expectedSafeName);
+
+        try {
+            if (fs.existsSync(expectedFullPath)) {
+                fs.unlinkSync(expectedFullPath);
+            }
+
+            vfs.writeFile(inputPath, content);
+            expect(fs.existsSync(expectedFullPath)).toBe(true);
+
+            const actualContent = fs.readFileSync(expectedFullPath, "utf8");
+            expect(actualContent).toBe(content);
+
+            expect(expectedSafeName).toBe(`${shortName}${ext}`);
+        } finally {
+            if (fs.existsSync(expectedFullPath)) {
+                fs.unlinkSync(expectedFullPath);
+            }
+        }
+    });
 });

src/vfs/createNodeFileSystem.ts

@@ -1,6 +1,7 @@
 import type { VirtualFileSystem } from "@/vfs/VirtualFileSystem";
 import fs from "fs";
 import path from "path";
+import { getFullExtension, makeSafeName } from "@/vfs/utils";
 
 function ensureInsideProjectRoot(filePath: string, root: string): void {
     if (!filePath.startsWith(root)) {
@@ -47,6 +48,12 @@ export function createNodeFileSystem(
             if (readonly) {
                 throw new Error("File system is readonly");
             }
+
+            const ext = getFullExtension(filePath);
+            const name = path.basename(filePath, ext);
+            const safeBase = makeSafeName(name, ext);
+            filePath = path.join(path.dirname(filePath), safeBase);
+
             ensureInsideProjectRoot(filePath, normalizedRoot);
             if (fs.existsSync(filePath)) {
                 ensureNotSymlink(filePath);

src/vfs/createVirtualFileSystem.spec.ts

@@ -27,4 +27,53 @@ describe("createVirtualFileSystem", () => {
         expect(vfs.exists(realPath)).toBe(true);
         expect(vfs.readFile(realPath).toString()).toBe("");
     });
+
+    it("should truncate and hash long filenames", () => {
+        const fs: Record<string, string> = {};
+        const vfs = createVirtualFileSystem("/", fs, false);
+
+        const longName = "A".repeat(300);
+        const content = "Test content";
+        const ext = ".md";
+
+        const inputPath = vfs.resolve("./", `${longName}${ext}`);
+
+        vfs.writeFile(inputPath, content);
+
+        const storedPaths = Object.keys(fs);
+        expect(storedPaths.length).toBe(1);
+
+        const storedPath = storedPaths[0]!;
+        expect(storedPath).toBeDefined();
+        expect(storedPath.length).toBeLessThanOrEqual(255);
+
+        const regex = new RegExp(
+            `^${longName.slice(0, 255 - ext.length - 9)}_[0-9a-f]{8}${ext}$`,
+        );
+        expect(storedPath).toMatch(regex);
+
+        expect(fs[storedPath]).toBe(Buffer.from(content).toString("base64"));
+    });
+
+    it("should not truncate or hash short filenames", () => {
+        const fs: Record<string, string> = {};
+        const vfs = createVirtualFileSystem("/", fs, false);
+
+        const shortName = "short-filename";
+        const content = "Test content";
+        const ext = ".md";
+
+        const inputPath = vfs.resolve("./", `${shortName}${ext}`);
+
+        vfs.writeFile(inputPath, content);
+
+        const storedPaths = Object.keys(fs);
+        expect(storedPaths.length).toBe(1);
+
+        const storedPath = storedPaths[0]!;
+        expect(storedPath).toBeDefined();
+
+        expect(storedPath).toBe(`${shortName}${ext}`);
+        expect(fs[storedPath]).toBe(Buffer.from(content).toString("base64"));
+    });
 });

src/vfs/createVirtualFileSystem.ts

@@ -1,5 +1,7 @@
 import normalize from "path-normalize";
 import type { VirtualFileSystem } from "@/vfs/VirtualFileSystem";
+import path from "path";
+import { getFullExtension, makeSafeName } from "@/vfs/utils";
 
 export function createVirtualFileSystem(
     root: string,
@@ -47,7 +49,13 @@ export function createVirtualFileSystem(
                     `Path '${filePath}' is outside of the root directory '${normalizedRoot}'`,
                 );
             }
-            const name = filePath.slice(normalizedRoot.length);
+            const relPath = filePath.slice(normalizedRoot.length);
+            const dir = path.dirname(relPath);
+            const ext = getFullExtension(relPath);
+            const base = path.basename(relPath, ext);
+
+            const safeName = makeSafeName(base, ext);
+            const name = path.join(dir, safeName);
             fs[name] =
                 typeof content === "string"
                     ? Buffer.from(content).toString("base64")

src/vfs/utils.ts

@@ -0,0 +1,41 @@
+import { sha256_sync } from "@ton/crypto";
+import path from "path";
+
+/**
+ * Ensures the resulting file name does not exceed the given maximum length.
+ * If too long, trims the name and appends a short hash to avoid collisions.
+ *
+ * @param name - The base file name without extension.
+ * @param ext - The file extension.
+ * @param maxLen - Maximum allowed length for the full file name (default: 255).
+ * @returns A safe file name within the specified length.
+ */
+export const makeSafeName = (
+    name: string,
+    ext: string,
+    maxLen = 255,
+): string => {
+    const full = name + ext;
+
+    if (full.length <= maxLen) {
+        return full;
+    }
+
+    const hash = sha256_sync(Buffer.from(name)).toString("hex").slice(0, 8);
+    const suffix = `_${hash}${ext}`;
+    const maxNameLen = maxLen - suffix.length;
+    const safeName = name.slice(0, maxNameLen);
+
+    return `${safeName}${suffix}`;
+};
+
+/**
+ * Returns the full extension of a file, including all parts after the first dot.
+ * - "file.txt" => ".txt"
+ * - "archive.tar.gz" => ".tar.gz"
+ */
+export const getFullExtension = (filename: string): string => {
+    const base = path.basename(filename);
+    const firstDotIndex = base.indexOf(".");
+    return firstDotIndex !== -1 ? base.slice(firstDotIndex) : "";
+};