SpectNet IDE

Visual Studio 2017/2019 integrated ZX Spectrum IDE for the Community

Unit Testing » Syntax Basics

SpectNetIde provides a somple programming language to describe Z80-related unit tests. You can add the .z80test files to your project and run the test in the Unit Test Explorer tool window. This document treats the syntax and semantics of the language.

Syntax Basics

The test language uses a special way of case-sensitivity. You can write the reserved keywords on lowercase. When you refer to Z80 CPU registers or flags, you can use either with lowercase or uppercase letters, but you cannot mix these cases. You can mix cases for identifiers, though they are searched for a case-insensitive manner.

Test Structure

A ZX Spectrum project may have zero, one, or more test files (files with .z80test extension). Before running them, the engine collects all .z80test files from the current project, and compiles them all.

A single test file may contain one or more test set. A test set is a collection of cohesive tests that all use the very same source code, as the basis of testing:

testset Introduction
    source "../Z80CodeFiles/CodeSamples.z80asm";

    // --- Other testset attributes    

    test AddAAndBWorksAsExpected
        // --- Other test attributes

        act call AddAAndB;

            // --- Here we describe the test assertions

A test can have a default act, such as in the sample above, or may have parameterized test cases:

// --- Wrapping test set omitted
test AddAAndBCallWorksAsExpected2
    params parA, parB, Z;
    case 1, 2, 0;
    case 2, 3, 0;
    case -6, 6, 1;

        a: parA;
        b: parB;

    act call AddAAndB;

        a == parA + parB;
        b == parB;
        .z == Z;

This test has three cases, as declared by the lines starting with the case keyword. When running them, the engine substitutes the parA, parB, and Z values with the values after case (fore each case).

To summarize:

Concept Description
test file A single container for test sets. Besides keeping test sets together in a single file, there’s no additional semantics.
test set A cohesive set of tests. A test set has a single source code file — this contains the code to test — shared between the test within the set.
test A single test that runs a piece of the source code to test. It may nest test cases.
test case Parameterized test. It runs the same code (although you can run different code) with the case-related parameters.

Syntax Elements

The test language contains several constituting elements that you can use in many places within the code, such as comments, expressions, identifiers, and so on. Here you can learn about them.


Comments can be single line or multi-line comments with the same syntax construct as you may use them in many curly-brace-languages, such as C++, Java, C#, etc.:

// --- This is a single line comment you can add to the end of the code lines

/* This is a multi-line comment the spans accross multiple lines, 
   including empty ones



The language syntax provides these types of literals:

  • Decimal numbers. You can use adjacent digits (0..9) to declare a decimal number. Examples: 16, 32768, 2354.
  • Hexadecimal numbers. You can use up to 4 hexadecimal digits (0..9, a..f or A..F) to declare a hexadecimal literal. The compiler looks for one of the # or 0x prefix, or one of the h or H suffixes to recognize them as hexadecimal. Here are a few samples:
  • Binary numbers. Literal starting with the one of the % or 0b prefix are taken into account as binary literals. You can follow the prefix with up to 16 0 or 1 digits. To make them more readable, you can separate adjacent digits with the underscore (_) character. These are all valid binary literals:

You can use negative number with the minus sign in front of them. Actually, the sign is not the part of the numeric literal, it is an operator.

  • Characters. You can put a character between double quotes (for example: "Q").
  • Strings. You can put a series of character between double quotes (for example: "Sinclair").

Here are a few samples:

"This is a string. The next sample is a single character"

Character and String Escapes

ZX Spectrum has a character set with special control characters such as AT, INK, PAPER, and so on.

SpectNetIde allows you to utilize special escape sequences to define ZX Spectrum-specific characters:

Escape Code Character
\i 0x10 INK
\p 0x11 PAPER
\f 0x12 FLASH
\b 0x13 BRIGHT
\o 0x15 OVER
\a 0x16 AT
\t 0x17 TAB
\P 0x60 pound sign
\C 0x7F copyright sign
\\ 0x5C backslash
\' 0x27 single quote
\" 0x22 double quote
\0 0x00 binary zero

Observe, some of these sequences have different values than their corresponding pairs in other languages, such as C, C++, C#, or Java.

To declare a character by its binary code, you can use the \xH or
\xHH sequences (H is a hexadecimal digit). For example, these escape sequence pairs are equivalent:


"\C by me"
"\x7f \x62y me"


You can use identifiers to refer to labels and other constants. Identifiers must start with a letter (a..z or A..Z) or the underscore character (_). The subsequent characters can be digits (0..9), too. Here are a few samples:


Theoretically, you can use as long identifiers as you want. I suggest you to make them no longer than 32 characters so that readers may read your code easily.