diff --git a/server/src/e2e/suite/folding.test.ts b/server/src/e2e/suite/folding.test.ts
new file mode 100644
index 00000000..c8e93a6b
--- /dev/null
+++ b/server/src/e2e/suite/folding.test.ts
@@ -0,0 +1,60 @@
+import * as vscode from "vscode"
+import * as assert from "node:assert"
+import {BaseTestSuite} from "./BaseTestSuite"
+import type {TestCase} from "./TestParser"
+
+suite("Folding Test Suite", () => {
+ const testSuite = new (class extends BaseTestSuite {
+ protected runTest(testFile: string, testCase: TestCase): void {
+ test(`Folding: ${testCase.name}`, async () => {
+ await this.replaceDocumentText(testCase.input)
+
+ const foldingRanges = await vscode.commands.executeCommand<vscode.FoldingRange[]>(
+ "vscode.executeFoldingRangeProvider",
+ this.document.uri,
+ )
+
+ if (foldingRanges.length <= 0) {
+ throw new Error("No folding ranges found")
+ }
+
+ const rangesInfo = foldingRanges
+ .map(range => `[${range.start + 1}, ${range.end + 1}]`)
+ .join(", ")
+
+ const lines = this.document.getText().split("\n")
+ const startLines = new Set(foldingRanges.map(range => range.start))
+
+ lines.forEach((lineContent, index) => {
+ if (startLines.has(index)) {
+ lines[index] = lineContent.replace(/\s*$/, "...")
+ }
+ })
+
+ const actualText = `${rangesInfo}\n${lines.join("\n")}`.trimEnd()
+ const expectedText = testCase.expected.trimEnd()
+
+ if (BaseTestSuite.UPDATE_SNAPSHOTS) {
+ this.updates.push({
+ filePath: testFile,
+ testName: testCase.name,
+ actual: actualText,
+ })
+ } else {
+ assert.deepStrictEqual(actualText, expectedText)
+ }
+ })
+ }
+ })()
+
+ suiteSetup(async function () {
+ this.timeout(10_000)
+ await testSuite.suiteSetup()
+ })
+
+ setup(async () => testSuite.setup())
+ teardown(async () => testSuite.teardown())
+ suiteTeardown(() => testSuite.suiteTeardown())
+
+ testSuite.runTestsFromDirectory("folding")
+})
diff --git a/server/src/e2e/suite/testcases/folding/assembly.test b/server/src/e2e/suite/testcases/folding/assembly.test
new file mode 100644
index 00000000..e0f557cd
--- /dev/null
+++ b/server/src/e2e/suite/testcases/folding/assembly.test
@@ -0,0 +1,215 @@
+========================================================================
+Assembly function with unknown instruction
+========================================================================
+asm fun foo() {
+ 10 PUSHINT2
+}
+------------------------------------------------------------------------
+[1, 2]
+asm fun foo() {...
+ 10 PUSHINT2
+}
+
+========================================================================
+Big assembly function with PUSHCONT
+========================================================================
+asm fun send(params: SendParameters) {
+ // Instructions are grouped, and the stack states they produce as a group are shown right after.
+ // In the end, our message Cell should have the following TL-B structure:
+ // message$_ {X:Type}
+ // info:CommonMsgInfoRelaxed
+ // init:(Maybe (Either StateInit ^StateInit))
+ // body:(Either X ^X)
+ // = MessageRelaxed X;
+
+ // Group 1: Rearrangements
+ 3 4 BLKSWAP
+ s2 XCHG0
+ // → Stack state
+ // s0: `params.bounce`
+ // s1: `params.to`
+ // s2: `params.value`
+ // s3: `params.data`
+ // s4: `params.code`
+ // s5: `params.body`
+ // s6: `params.mode`
+ // For brevity, the "params" prefix will be omitted from now on.
+
+ // Group 2: Storing the `bounce`, `to` and `value` into a Builder
+ NEWC
+ b{01} STSLICECONST // store tag = $0 and ihr_disabled = true
+ 1 STI // store `bounce`
+ b{000} STSLICECONST // store bounced = false and src = addr_none
+ STSLICE // store `to`
+ SWAP
+ STGRAMS // store `value`
+ 105 PUSHINT // 1 + 4 + 4 + 64 + 32
+ STZEROES // store currency_collection, ihr_fee, fwd_fee, created_lt and created_at
+ // → Stack state
+ // s0: Builder
+ // s1: `data`
+ // s2: `code`
+ // s3: `body`
+ // s4: `mode`
+
+ // Group 3: Placing the Builder after code and data, then checking those for nullability
+ s2 XCHG0
+ DUP2
+ ISNULL
+ SWAP
+ ISNULL
+ MUL // note that -1 * -1 wraps back to -1
+ // → Stack state
+ // s0: -1 (true) if `data` and `code` are both null, 0 (false) otherwise
+ // s1: `code`
+ // s2: `data`
+ // s3: Builder
+ // s4: `body`
+ // s5: `mode`
+
+ // Group 4: Left branch of the IFELSE, executed if s0 is -1 (true)
+ <{
+ DROP2 // drop `data` and `code`, since either of those is null
+ NULL // push a single null
+ SWAP // place Builder on top
+ }> PUSHCONT
+
+ // Group 4: Right branch of the IFELSE, executed if s0 is 0 (false)
+ <{
+ // _ split_depth:(Maybe (## 5))
+ // special:(Maybe TickTock)
+ // code:(Maybe ^Cell)
+ // data:(Maybe ^Cell)
+ // library:(Maybe ^Cell)
+ // = StateInit;
+ NEWC // start composing StateInit
+ b{00} STSLICECONST // split_depth and special
+ STDICT // store code
+ STDICT // store data
+ b{0} STSLICECONST // store library
+ ENDC // end composing StateInit
+ SWAP // place Builder on top
+ b{1} STSLICECONST // an extra bit for storing StateInit as ref
+ }> PUSHCONT
+
+ // Group 4: IFELSE that does the branching shown above
+ IFELSE
+ // → Stack state
+ // s0: Builder
+ // s1: null or StateInit
+ // s2: `body`
+ // s3: `mode`
+
+ // Group 5: Finalizing the message
+ STDICT // store StateInit
+ STDICT // store `body` as ref with an extra Maybe bit, since `body` might be null
+ ENDC
+ // → Stack state
+ // s0: Cell
+ // s1: `mode`
+
+ // Group 6: Sending the message, with `mode` on top
+ SWAP
+ SENDRAWMSG // https://github.com/tact-lang/tact/issues/1558
+}
+------------------------------------------------------------------------
+[1, 98], [56, 59], [63, 77]
+asm fun send(params: SendParameters) {...
+ // Instructions are grouped, and the stack states they produce as a group are shown right after.
+ // In the end, our message Cell should have the following TL-B structure:
+ // message$_ {X:Type}
+ // info:CommonMsgInfoRelaxed
+ // init:(Maybe (Either StateInit ^StateInit))
+ // body:(Either X ^X)
+ // = MessageRelaxed X;
+
+ // Group 1: Rearrangements
+ 3 4 BLKSWAP
+ s2 XCHG0
+ // → Stack state
+ // s0: `params.bounce`
+ // s1: `params.to`
+ // s2: `params.value`
+ // s3: `params.data`
+ // s4: `params.code`
+ // s5: `params.body`
+ // s6: `params.mode`
+ // For brevity, the "params" prefix will be omitted from now on.
+
+ // Group 2: Storing the `bounce`, `to` and `value` into a Builder
+ NEWC
+ b{01} STSLICECONST // store tag = $0 and ihr_disabled = true
+ 1 STI // store `bounce`
+ b{000} STSLICECONST // store bounced = false and src = addr_none
+ STSLICE // store `to`
+ SWAP
+ STGRAMS // store `value`
+ 105 PUSHINT // 1 + 4 + 4 + 64 + 32
+ STZEROES // store currency_collection, ihr_fee, fwd_fee, created_lt and created_at
+ // → Stack state
+ // s0: Builder
+ // s1: `data`
+ // s2: `code`
+ // s3: `body`
+ // s4: `mode`
+
+ // Group 3: Placing the Builder after code and data, then checking those for nullability
+ s2 XCHG0
+ DUP2
+ ISNULL
+ SWAP
+ ISNULL
+ MUL // note that -1 * -1 wraps back to -1
+ // → Stack state
+ // s0: -1 (true) if `data` and `code` are both null, 0 (false) otherwise
+ // s1: `code`
+ // s2: `data`
+ // s3: Builder
+ // s4: `body`
+ // s5: `mode`
+
+ // Group 4: Left branch of the IFELSE, executed if s0 is -1 (true)
+ <{...
+ DROP2 // drop `data` and `code`, since either of those is null
+ NULL // push a single null
+ SWAP // place Builder on top
+ }> PUSHCONT
+
+ // Group 4: Right branch of the IFELSE, executed if s0 is 0 (false)
+ <{...
+ // _ split_depth:(Maybe (## 5))
+ // special:(Maybe TickTock)
+ // code:(Maybe ^Cell)
+ // data:(Maybe ^Cell)
+ // library:(Maybe ^Cell)
+ // = StateInit;
+ NEWC // start composing StateInit
+ b{00} STSLICECONST // split_depth and special
+ STDICT // store code
+ STDICT // store data
+ b{0} STSLICECONST // store library
+ ENDC // end composing StateInit
+ SWAP // place Builder on top
+ b{1} STSLICECONST // an extra bit for storing StateInit as ref
+ }> PUSHCONT
+
+ // Group 4: IFELSE that does the branching shown above
+ IFELSE
+ // → Stack state
+ // s0: Builder
+ // s1: null or StateInit
+ // s2: `body`
+ // s3: `mode`
+
+ // Group 5: Finalizing the message
+ STDICT // store StateInit
+ STDICT // store `body` as ref with an extra Maybe bit, since `body` might be null
+ ENDC
+ // → Stack state
+ // s0: Cell
+ // s1: `mode`
+
+ // Group 6: Sending the message, with `mode` on top
+ SWAP
+ SENDRAWMSG // https://github.com/tact-lang/tact/issues/1558
+}
diff --git a/server/src/e2e/suite/testcases/folding/contract.test b/server/src/e2e/suite/testcases/folding/contract.test
new file mode 100644
index 00000000..f5652763
--- /dev/null
+++ b/server/src/e2e/suite/testcases/folding/contract.test
@@ -0,0 +1,169 @@
+========================================================================
+Simple Contract
+========================================================================
+primitive Int;
+
+contract A {
+
+}
+------------------------------------------------------------------------
+[3, 4]
+primitive Int;
+
+contract A {...
+
+}
+
+========================================================================
+Contract with receiver
+========================================================================
+primitive Int;
+
+contract A {
+ receive("Test") {
+ let a: Int = 32;
+ }
+}
+------------------------------------------------------------------------
+[3, 6], [4, 5]
+primitive Int;
+
+contract A {...
+ receive("Test") {...
+ let a: Int = 32;
+ }
+}
+
+========================================================================
+Contract with external
+========================================================================
+contract Name {
+ external("external") {
+ // some code
+ }
+}
+------------------------------------------------------------------------
+[1, 4], [2, 3]
+contract Name {...
+ external("external") {...
+ // some code
+ }
+}
+
+========================================================================
+Contract with bounced and filled body
+========================================================================
+contract A {
+ bounced(msg: Int) {
+ while (true) {
+ let start = false;
+ }
+ }
+}
+------------------------------------------------------------------------
+[1, 6], [2, 5], [3, 4]
+contract A {...
+ bounced(msg: Int) {...
+ while (true) {...
+ let start = false;
+ }
+ }
+}
+
+========================================================================
+Contract with nested blocks
+========================================================================
+contract Nested {
+ fun calculate() {
+ {
+ let x = 10;
+ {
+ let y = x * 2;
+ log(y);
+ }
+ }
+ }
+}
+------------------------------------------------------------------------
+[1, 10], [2, 9], [3, 8], [5, 7]
+contract Nested {...
+ fun calculate() {...
+ {...
+ let x = 10;
+ {...
+ let y = x * 2;
+ log(y);
+ }
+ }
+ }
+}
+
+========================================================================
+Contract with message handlers
+========================================================================
+contract Wallet {
+ receive("Deposit") {
+ balance += msg.amount;
+ }
+
+ receive("Withdraw") {
+ if (balance >= msg.amount) {
+ send(msg.amount);
+ balance -= msg.amount;
+ }
+ }
+}
+------------------------------------------------------------------------
+[1, 11], [2, 3], [6, 10], [7, 9]
+contract Wallet {...
+ receive("Deposit") {...
+ balance += msg.amount;
+ }
+
+ receive("Withdraw") {...
+ if (balance >= msg.amount) {...
+ send(msg.amount);
+ balance -= msg.amount;
+ }
+ }
+}
+
+========================================================================
+Contract with if-else
+========================================================================
+contract Counter {
+ fun increment() {
+ if (value < 10) {
+ value += 1;
+ } else {
+ value = 0;
+ }
+ }
+}
+------------------------------------------------------------------------
+[1, 8], [2, 7], [3, 4], [5, 6]
+contract Counter {...
+ fun increment() {...
+ if (value < 10) {...
+ value += 1;
+ } else {...
+ value = 0;
+ }
+ }
+}
+
+========================================================================
+Contract with empty init
+========================================================================
+contract A {
+ init() {
+
+ }
+}
+------------------------------------------------------------------------
+[1, 4], [2, 3]
+contract A {...
+ init() {...
+
+ }
+}
diff --git a/server/src/e2e/suite/testcases/folding/functions.test b/server/src/e2e/suite/testcases/folding/functions.test
new file mode 100644
index 00000000..cce14379
--- /dev/null
+++ b/server/src/e2e/suite/testcases/folding/functions.test
@@ -0,0 +1,63 @@
+========================================================================
+Global function
+========================================================================
+primitive Int;
+
+fun foo(size: Int) {
+ // some code
+}
+
+fun test() {
+ foo(42);
+}
+------------------------------------------------------------------------
+[3, 4], [7, 8]
+primitive Int;
+
+fun foo(size: Int) {...
+ // some code
+}
+
+fun test() {...
+ foo(42);
+}
+
+========================================================================
+Global function with Cell
+========================================================================
+fun foo() {
+ const cell = TokenNotification{
+ query_id: 10,
+ amount: 20,
+ from: address(""),
+ }.toCell()/* Size: 367 bits plus up to 120 bits */
+}
+------------------------------------------------------------------------
+[1, 6], [2, 5]
+fun foo() {...
+ const cell = TokenNotification{...
+ query_id: 10,
+ amount: 20,
+ from: address(""),
+ }.toCell()/* Size: 367 bits plus up to 120 bits */
+}
+
+========================================================================
+Global function with foreach
+========================================================================
+fun foo() {
+ let a: map<Int, String> = emptyMap();
+ foreach (key, value in a) {
+ dump(key)
+ dump(value)
+ }
+}
+------------------------------------------------------------------------
+[1, 6], [3, 5]
+fun foo() {...
+ let a: map<Int, String> = emptyMap();
+ foreach (key, value in a) {...
+ dump(key)
+ dump(value)
+ }
+}
diff --git a/server/src/e2e/suite/testcases/folding/struct.test b/server/src/e2e/suite/testcases/folding/struct.test
new file mode 100644
index 00000000..0e45061e
--- /dev/null
+++ b/server/src/e2e/suite/testcases/folding/struct.test
@@ -0,0 +1,13 @@
+========================================================================
+Single Struct
+========================================================================
+primitive Int;
+struct Foo {
+ a: Int;
+}
+------------------------------------------------------------------------
+[2, 3]
+primitive Int;
+struct Foo {...
+ a: Int;
+}
diff --git a/server/src/e2e/suite/testcases/folding/trait.test b/server/src/e2e/suite/testcases/folding/trait.test
new file mode 100644
index 00000000..4d48155d
--- /dev/null
+++ b/server/src/e2e/suite/testcases/folding/trait.test
@@ -0,0 +1,11 @@
+========================================================================
+Simple Trait
+========================================================================
+trait Foo {
+ Bar: Int;
+}
+------------------------------------------------------------------------
+[1, 2]
+trait Foo {...
+ Bar: Int;
+}