add tests for cimport

tests/language_features/cimport.zig

@@ -0,0 +1,85 @@
+const std = @import("std");
+const zls = @import("zls");
+
+const Ast = std.zig.Ast;
+
+const translate_c = zls.translate_c;
+
+const allocator: std.mem.Allocator = std.testing.allocator;
+
+test "convertCInclude - empty" {
+    try testConvertCInclude("@cImport()", "");
+    try testConvertCInclude("@cImport({})", "");
+    try testConvertCInclude("@cImport({{}, {}})", "");
+}
+
+test "convertCInclude - cInclude" {
+    try testConvertCInclude(
+        \\@cImport(@cInclude("foo.zig"))
+    ,
+        \\#include <foo.zig>
+    );
+
+    try testConvertCInclude(
+        \\@cImport(@cInclude("foo.zig"), @cInclude("bar.zig"))
+    ,
+        \\#include <foo.zig>
+        \\#include <bar.zig>
+    );
+}
+
+test "translate_c - cDefine" {
+    try testConvertCInclude(
+        \\@cImport(@cDefine("FOO", "BAR"))
+    ,
+        \\#define FOO BAR
+    );
+    try testConvertCInclude(
+        \\@cImport(@cDefine("FOO", {}))
+    ,
+        \\#define FOO
+    );
+}
+
+test "translate_c - cUndef" {
+    try testConvertCInclude(
+        \\@cImport(@cUndef("FOO"))
+    ,
+        \\#undef FOO
+    );
+}
+
+fn testConvertCInclude(cimport_source: []const u8, expected: []const u8) !void {
+    const source: [:0]u8 = try std.fmt.allocPrintZ(allocator, "const c = {s};", .{cimport_source});
+    defer allocator.free(source);
+
+    var ast = try std.zig.parse(allocator, source);
+    defer ast.deinit(allocator);
+
+    const main_tokens = ast.nodes.items(.main_token);
+
+    const node: Ast.Node.Index = blk: {
+        for (ast.nodes.items(.tag)) |tag, index| {
+            switch (tag) {
+                .builtin_call_two,
+                .builtin_call_two_comma,
+                .builtin_call,
+                .builtin_call_comma,
+                => {},
+                else => continue,
+            }
+            
+            if(!std.mem.eql(u8, ast.tokenSlice(main_tokens[index]), "@cImport")) continue;
+
+            break :blk @intCast(Ast.Node.Index, index);
+        }
+        return error.TestUnexpectedResult; // source doesn't contain a cImport
+    };
+
+    const output = try translate_c.convertCInclude(allocator, ast, node);
+    defer allocator.free(output);
+
+    const trimmed_output = std.mem.trimRight(u8, output, &.{'\n'});
+
+    try std.testing.expectEqualStrings(expected, trimmed_output);
+}

tests/tests.zig

@@ -9,5 +9,6 @@ test {
     _ = @import("lsp_features/semantic_tokens.zig");
     _ = @import("lsp_features/inlay_hints.zig");
 
-    // TODO Language features
+    // Language features
+    _ = @import("language_features/cimport.zig");
 }