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Fix: use if/else pattern for skip() guards in unit tests #1

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Fix: use if/else pattern for skip() guards in unit tests #1

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46 changes: 26 additions & 20 deletions tests/test_assembler.nim
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Original file line number Diff line number Diff line change
Expand Up @@ -19,46 +19,52 @@ suite "Assembler Module Tests":
test "assembleInstruction encodes NOP correctly":
if not isKeystoneAvailable():
skip()
let bytes = assembleInstruction("nop", archX64)
check bytes.len == 1
check bytes[0] == 0x90'u8
else:
let bytes = assembleInstruction("nop", archX64)
check bytes.len == 1
check bytes[0] == 0x90'u8

test "assembleInstruction encodes RET correctly":
if not isKeystoneAvailable():
skip()
let bytes = assembleInstruction("ret", archX64)
check bytes.len == 1
check bytes[0] == 0xC3'u8
else:
let bytes = assembleInstruction("ret", archX64)
check bytes.len == 1
check bytes[0] == 0xC3'u8

test "assembleInstruction returns empty seq for invalid instruction":
if not isKeystoneAvailable():
skip()
let bytes = assembleInstruction("notavalidinstruction xyz_!!!", archX64)
check bytes.len == 0
else:
let bytes = assembleInstruction("notavalidinstruction xyz_!!!", archX64)
check bytes.len == 0

test "assembleBlock encodes multiple semicolon-separated instructions":
if not isKeystoneAvailable():
skip()
let output = assembleBlock("nop; nop; ret", archX64)
check output.bytes.len == 3
check output.statCount == 3
check output.bytes[0] == 0x90'u8
check output.bytes[1] == 0x90'u8
check output.bytes[2] == 0xC3'u8
else:
let output = assembleBlock("nop; nop; ret", archX64)
check output.bytes.len == 3
check output.statCount == 3
check output.bytes[0] == 0x90'u8
check output.bytes[1] == 0x90'u8
check output.bytes[2] == 0xC3'u8

test "assembleBlock returns empty output for invalid instructions":
if not isKeystoneAvailable():
skip()
let output = assembleBlock("notvalid !!!", archX64)
check output.bytes.len == 0
check output.statCount == 0
else:
let output = assembleBlock("notvalid !!!", archX64)
check output.bytes.len == 0
check output.statCount == 0

test "assembleInstruction handles x86 32-bit mode":
if not isKeystoneAvailable():
skip()
let bytes = assembleInstruction("nop", archX86)
check bytes.len == 1
check bytes[0] == 0x90'u8
else:
let bytes = assembleInstruction("nop", archX86)
check bytes.len == 1
check bytes[0] == 0x90'u8

test "makeNops generates the correct number of NOP bytes":
let nops = makeNops(4)
Expand Down
105 changes: 55 additions & 50 deletions tests/test_disassembler.nim
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Expand Up @@ -6,13 +6,6 @@
# unconditionally.
import unittest, disassembler, binary

# ---------------------------------------------------------------------------
# Helper: skip a test when Capstone is not installed.
# ---------------------------------------------------------------------------
template requireCapstone() =
if not isCapstoneAvailable():
skip()

# ---------------------------------------------------------------------------
# Suite: Capstone availability probe
# ---------------------------------------------------------------------------
Expand All @@ -34,59 +27,71 @@ suite "disassembleBytes":
check result.len == 0

test "NOP byte (0x90) decodes as 'nop' on x64":
requireCapstone()
let data: seq[byte] = @[0x90'u8]
let instrs = disassembleBytes(data, 0x1000'u64, archX64)
check instrs.len == 1
check instrs[0].mnemonic == "nop"
check instrs[0].address == 0x1000'u64
check instrs[0].rawBytes == @[0x90'u8]
if not isCapstoneAvailable():
skip()
else:
let data: seq[byte] = @[0x90'u8]
let instrs = disassembleBytes(data, 0x1000'u64, archX64)
check instrs.len == 1
check instrs[0].mnemonic == "nop"
check instrs[0].address == 0x1000'u64
check instrs[0].rawBytes == @[0x90'u8]

test "RET byte (0xC3) decodes as 'ret' on x64":
requireCapstone()
let data: seq[byte] = @[0xC3'u8]
let instrs = disassembleBytes(data, 0x2000'u64, archX64)
check instrs.len == 1
check instrs[0].mnemonic == "ret"
check instrs[0].address == 0x2000'u64
if not isCapstoneAvailable():
skip()
else:
let data: seq[byte] = @[0xC3'u8]
let instrs = disassembleBytes(data, 0x2000'u64, archX64)
check instrs.len == 1
check instrs[0].mnemonic == "ret"
check instrs[0].address == 0x2000'u64

test "Function prologue bytes decode to push/mov on x64":
requireCapstone()
# 55 push rbp
# 48 89 E5 mov rbp, rsp
let data: seq[byte] = @[0x55'u8, 0x48'u8, 0x89'u8, 0xE5'u8]
let instrs = disassembleBytes(data, 0x4000'u64, archX64)
check instrs.len == 2
check instrs[0].mnemonic == "push"
check instrs[0].address == 0x4000'u64
check instrs[1].mnemonic == "mov"
check instrs[1].address == 0x4001'u64
if not isCapstoneAvailable():
skip()
else:
# 55 push rbp
# 48 89 E5 mov rbp, rsp
let data: seq[byte] = @[0x55'u8, 0x48'u8, 0x89'u8, 0xE5'u8]
let instrs = disassembleBytes(data, 0x4000'u64, archX64)
check instrs.len == 2
check instrs[0].mnemonic == "push"
check instrs[0].address == 0x4000'u64
check instrs[1].mnemonic == "mov"
check instrs[1].address == 0x4001'u64

test "Multiple instructions have sequential addresses":
requireCapstone()
# 90 = nop (1 byte), C3 = ret (1 byte)
let data: seq[byte] = @[0x90'u8, 0xC3'u8]
let instrs = disassembleBytes(data, 0x5000'u64, archX64)
check instrs.len == 2
check instrs[0].address == 0x5000'u64
check instrs[1].address == 0x5001'u64
if not isCapstoneAvailable():
skip()
else:
# 90 = nop (1 byte), C3 = ret (1 byte)
let data: seq[byte] = @[0x90'u8, 0xC3'u8]
let instrs = disassembleBytes(data, 0x5000'u64, archX64)
check instrs.len == 2
check instrs[0].address == 0x5000'u64
check instrs[1].address == 0x5001'u64

test "Invalid/garbage bytes return empty or partial result without crashing":
requireCapstone()
# 0xFF 0xFF is not a valid x64 instruction at this position; Capstone
# may decode it partially or return empty, but must not raise.
let data: seq[byte] = @[0xFF'u8, 0xFF'u8, 0xFF'u8, 0xFF'u8]
let instrs = disassembleBytes(data, 0'u64, archX64)
# We only check it did not crash; result may be empty or partial.
check instrs.len >= 0
if not isCapstoneAvailable():
skip()
else:
# 0xFF 0xFF is not a valid x64 instruction at this position; Capstone
# may decode it partially or return empty, but must not raise.
let data: seq[byte] = @[0xFF'u8, 0xFF'u8, 0xFF'u8, 0xFF'u8]
let instrs = disassembleBytes(data, 0'u64, archX64)
# We only check it did not crash; result may be empty or partial.
check instrs.len >= 0

test "Base address is reflected in instruction addresses":
requireCapstone()
let data: seq[byte] = @[0x90'u8]
let base = 0xDEAD0000'u64
let instrs = disassembleBytes(data, base, archX64)
check instrs.len == 1
check instrs[0].address == base
if not isCapstoneAvailable():
skip()
else:
let data: seq[byte] = @[0x90'u8]
let base = 0xDEAD0000'u64
let instrs = disassembleBytes(data, base, archX64)
check instrs.len == 1
check instrs[0].address == base

# ---------------------------------------------------------------------------
# Suite: disassembleSection (pure-Nim paths that do not need Capstone)
Expand Down
131 changes: 70 additions & 61 deletions tests/test_emulator.nim
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Original file line number Diff line number Diff line change
Expand Up @@ -35,9 +35,10 @@ suite "Emulator Module Tests":
test "closeEmulator is safe to call twice on a real context":
if not isUnicornAvailable():
skip()
var ctx = createEmulator(archX64)
closeEmulator(ctx)
closeEmulator(ctx)
else:
var ctx = createEmulator(archX64)
closeEmulator(ctx)
closeEmulator(ctx)

test "loadMemory returns false when engine is nil":
var ctx = EmulatorContext()
Expand All @@ -51,10 +52,11 @@ suite "Emulator Module Tests":
test "loadMemory succeeds with valid data when Unicorn available":
if not isUnicornAvailable():
skip()
var ctx = createEmulator(archX64)
defer: closeEmulator(ctx)
let data: seq[byte] = @[0x90'u8, 0x90'u8]
check ctx.loadMemory(0x00401000'u64, data) == true
else:
var ctx = createEmulator(archX64)
defer: closeEmulator(ctx)
let data: seq[byte] = @[0x90'u8, 0x90'u8]
check ctx.loadMemory(0x00401000'u64, data) == true

test "readRegister returns 0 for nil engine":
let ctx = EmulatorContext()
Expand Down Expand Up @@ -83,86 +85,92 @@ suite "Emulator Module Tests":
test "register write and read round-trip":
if not isUnicornAvailable():
skip()
var ctx = createEmulator(archX64)
defer: closeEmulator(ctx)
check ctx.writeRegister(UC_X86_REG_RAX, 0xDEADBEEF'u64) == true
check ctx.readRegister(UC_X86_REG_RAX) == 0xDEADBEEF'u64
else:
var ctx = createEmulator(archX64)
defer: closeEmulator(ctx)
check ctx.writeRegister(UC_X86_REG_RAX, 0xDEADBEEF'u64) == true
check ctx.readRegister(UC_X86_REG_RAX) == 0xDEADBEEF'u64

test "register write and read round-trip for RBX":
if not isUnicornAvailable():
skip()
var ctx = createEmulator(archX64)
defer: closeEmulator(ctx)
check ctx.writeRegister(UC_X86_REG_RBX, 0x1234'u64) == true
check ctx.readRegister(UC_X86_REG_RBX) == 0x1234'u64
else:
var ctx = createEmulator(archX64)
defer: closeEmulator(ctx)
check ctx.writeRegister(UC_X86_REG_RBX, 0x1234'u64) == true
check ctx.readRegister(UC_X86_REG_RBX) == 0x1234'u64

test "emulate a NOP sled executes without error":
if not isUnicornAvailable():
skip()
var ctx = createEmulator(archX64)
defer: closeEmulator(ctx)
else:
var ctx = createEmulator(archX64)
defer: closeEmulator(ctx)

# Four NOP bytes. The emulator stops after maxInstructions = 4.
let code: seq[byte] = @[0x90'u8, 0x90'u8, 0x90'u8, 0x90'u8]
let base = 0x00401000'u64
check ctx.loadMemory(base, code) == true
# Four NOP bytes. The emulator stops after maxInstructions = 4.
let code: seq[byte] = @[0x90'u8, 0x90'u8, 0x90'u8, 0x90'u8]
let base = 0x00401000'u64
check ctx.loadMemory(base, code) == true

let res = ctx.emulateRange(base, base + uint64(code.len), 4)
check res.success == true
let res = ctx.emulateRange(base, base + uint64(code.len), 4)
check res.success == true

test "emulate mov eax, 42 and read register result":
if not isUnicornAvailable():
skip()
var ctx = createEmulator(archX64)
defer: closeEmulator(ctx)
else:
var ctx = createEmulator(archX64)
defer: closeEmulator(ctx)

# Encoding: b8 2a 00 00 00 (mov eax, 42)
let code: seq[byte] = @[0xb8'u8, 0x2a'u8, 0x00'u8, 0x00'u8, 0x00'u8]
let base = 0x00401000'u64
check ctx.loadMemory(base, code) == true
# Encoding: b8 2a 00 00 00 (mov eax, 42)
let code: seq[byte] = @[0xb8'u8, 0x2a'u8, 0x00'u8, 0x00'u8, 0x00'u8]
let base = 0x00401000'u64
check ctx.loadMemory(base, code) == true

# Execute exactly 1 instruction and verify EAX.
let res = ctx.emulateRange(base, base + uint64(code.len), 1)
check res.success == true
check ctx.readRegister(UC_X86_REG_EAX) == 42'u64
# Execute exactly 1 instruction and verify EAX.
let res = ctx.emulateRange(base, base + uint64(code.len), 1)
check res.success == true
check ctx.readRegister(UC_X86_REG_EAX) == 42'u64

test "emulate xor rax, rax zeroes the register":
if not isUnicornAvailable():
skip()
var ctx = createEmulator(archX64)
defer: closeEmulator(ctx)
else:
var ctx = createEmulator(archX64)
defer: closeEmulator(ctx)

check ctx.writeRegister(UC_X86_REG_RAX, 0xFFFF'u64) == true
check ctx.writeRegister(UC_X86_REG_RAX, 0xFFFF'u64) == true

# Encoding: 48 31 c0 (xor rax, rax)
let code: seq[byte] = @[0x48'u8, 0x31'u8, 0xc0'u8]
let base = 0x00401000'u64
check ctx.loadMemory(base, code) == true
# Encoding: 48 31 c0 (xor rax, rax)
let code: seq[byte] = @[0x48'u8, 0x31'u8, 0xc0'u8]
let base = 0x00401000'u64
check ctx.loadMemory(base, code) == true

let res = ctx.emulateRange(base, base + uint64(code.len), 1)
check res.success == true
check ctx.readRegister(UC_X86_REG_RAX) == 0'u64
let res = ctx.emulateRange(base, base + uint64(code.len), 1)
check res.success == true
check ctx.readRegister(UC_X86_REG_RAX) == 0'u64

test "code hook fires for each instruction in a NOP sled":
if not isUnicornAvailable():
skip()
var ctx = createEmulator(archX64)
defer: closeEmulator(ctx)
else:
var ctx = createEmulator(archX64)
defer: closeEmulator(ctx)

var counter: int = 0
var counter: int = 0

proc countHook(uc: ptr UcEngine, address: uint64, size: uint32,
userData: pointer) {.cdecl.} =
var p = cast[ptr int](userData)
p[] += 1
proc countHook(uc: ptr UcEngine, address: uint64, size: uint32,
userData: pointer) {.cdecl.} =
var p = cast[ptr int](userData)
p[] += 1

let base = 0x00401000'u64
let code: seq[byte] = @[0x90'u8, 0x90'u8, 0x90'u8, 0x90'u8]
check ctx.loadMemory(base, code) == true
check ctx.addCodeHook(countHook, addr counter) == true
let base = 0x00401000'u64
let code: seq[byte] = @[0x90'u8, 0x90'u8, 0x90'u8, 0x90'u8]
check ctx.loadMemory(base, code) == true
check ctx.addCodeHook(countHook, addr counter) == true

discard ctx.emulateRange(base, base + uint64(code.len), 4)
check counter == 4
discard ctx.emulateRange(base, base + uint64(code.len), 4)
check counter == 4

test "loadBinary returns false when engine is nil":
var ctx = EmulatorContext()
Expand All @@ -172,11 +180,12 @@ suite "Emulator Module Tests":
test "loadBinary returns false for unknown binary format":
if not isUnicornAvailable():
skip()
var ctx = createEmulator(archX64)
defer: closeEmulator(ctx)
# parseBinary on a nonexistent file returns bfUnknown with no sections.
let info = parseBinary("nonexistent_binary_xyz.elf")
check ctx.loadBinary(info, ".text") == false
else:
var ctx = createEmulator(archX64)
defer: closeEmulator(ctx)
# parseBinary on a nonexistent file returns bfUnknown with no sections.
let info = parseBinary("nonexistent_binary_xyz.elf")
check ctx.loadBinary(info, ".text") == false

test "isUnicornAvailable does not raise when library is missing":
# Regardless of whether Unicorn is installed, the call must not raise.
Expand Down
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