[core] Backend agnostic impl for tests

Author: burdzwastaken

.github/workflows/ci.yml

@@ -39,14 +39,17 @@ jobs:
       - name: Build (zware native)
         run: zig build -Dbackend=zware -Doptimize=ReleaseSafe
 
+      - name: Run tests (zware native)
+        run: zig build test -Dbackend=zware
+
       - name: Build (zware wasm32)
         run: zig build -Dbackend=zware wasm -Doptimize=ReleaseSmall
 
       - name: Build (wasmer)
-        run: zig build -Doptimize=ReleaseSafe
+        run: zig build -Dbackend=wasmer -Doptimize=ReleaseSafe
 
-      - name: Run tests
-        run: zig build test
+      - name: Run tests (wasmer)
+        run: zig build test -Dbackend=wasmer
 
       - name: Setup Go
         uses: actions/setup-go@v5

build.zig.zon

@@ -26,7 +26,7 @@
         },
         .zware = .{
             .url = "https://github.com/burdzwastaken/zware/archive/refs/heads/master.tar.gz",
-            .hash = "zware-0.0.1-ZA7j6dLpBAAIiASxs8G9aOkUqRNDjEtBrblF5QvgoNVV",
+            .hash = "zware-0.0.1-ZA7j6U_qBAAfIr6ZENpSVSzxpBG5nDG9xxqx_cAi6IDC",
         },
     },
     .paths = .{

flake.nix

@@ -43,6 +43,7 @@
             pkgs.open-policy-agent
             pkgs.zig
             pkgs.zls
+            pkgs.wabt
             wasmer
           ];
 
@@ -51,11 +52,12 @@
           shellHook = ''
             echo "zig-opa-wasm development environment"
             echo ""
-            echo "  go:     $(go version)"
-            echo "  opa:    $(opa version | grep '^Version:' | cut -d' ' -f2)"
-            echo "  wasmer: $(wasmer --version 2>/dev/null | cut -d' ' -f2 || echo 'binary')"
-            echo "  zig:    $(zig version)"
-            echo "  zls:    $(zls --version)"
+            echo "  go:       $(go version)"
+            echo "  opa:      $(opa version | grep '^Version:' | cut -d' ' -f2)"
+            echo "  wasmer:   $(wasmer --version 2>/dev/null | cut -d' ' -f2 || echo 'binary')"
+            echo "  wasm2wat: $(wasm2wat --version)"
+            echo "  zig:      $(zig version)"
+            echo "  zls:      $(zls --version)"
             echo ""
           '';
         };

src/backends/wasmer.zig

@@ -535,6 +535,7 @@ fn serializeResult(allocator: std.mem.Allocator, ctx: *OpaContext, value: std.js
 }
 
 test "wasmer backend init" {
+    if (!is_wasmer) return;
     var wb = try WasmerBackend.init(std.testing.allocator);
     defer wb.deinit();
 
@@ -543,6 +544,7 @@ test "wasmer backend init" {
 }
 
 test "wasmer load and instantiate module" {
+    if (!is_wasmer) return;
     const wasm_bytes = @embedFile("test_add_wasm");
     var wb = try WasmerBackend.init(std.testing.allocator);
     defer wb.deinit();

src/evaluation.zig

@@ -149,13 +149,17 @@ test "evaluation context creation" {
     const testing = std.testing;
     const Policy = @import("policy.zig").Policy;
     const Inst = @import("instance.zig").Instance;
-    const WasmerBackend = @import("backends/wasmer.zig").WasmerBackend;
+    const options = @import("options");
+    const BackendImpl = switch (options.backend) {
+        .wasmer => @import("backends/wasmer.zig").WasmerBackend,
+        .zware => @import("backends/zware.zig").ZwareBackend,
+    };
 
     const wasm_bytes = @embedFile("test_example_wasm");
-    var wasmer_backend = try WasmerBackend.init(testing.allocator);
-    defer wasmer_backend.deinit();
+    var wasm_backend = try BackendImpl.init(testing.allocator);
+    defer wasm_backend.deinit();
 
-    var b = wasmer_backend.asBackend();
+    var b = wasm_backend.asBackend();
     var policy = try Policy.load(testing.allocator, &b, wasm_bytes);
     defer policy.deinit();
 

src/instance.zig

@@ -2,10 +2,19 @@
 
 const std = @import("std");
 const backend = @import("backends/backend.zig");
-const wasmer = @import("backends/wasmer.zig");
+const options = @import("options");
 const Policy = @import("policy.zig").Policy;
 const MemoryManager = @import("memory/manager.zig").MemoryManager;
 
+const BackendImpl = switch (options.backend) {
+    .wasmer => @import("backends/wasmer.zig").WasmerBackend,
+    .zware => @import("backends/zware.zig").ZwareBackend,
+};
+const LogLevel = switch (options.backend) {
+    .wasmer => @import("backends/wasmer.zig").LogLevel,
+    .zware => @import("backends/zware.zig").LogLevel,
+};
+
 /// A live OPA WASM instance ready for policy evaluation.
 pub const Instance = struct {
     const Self = @This();
@@ -124,10 +133,10 @@ pub const Instance = struct {
         return self.evaluateById(entrypoint_id, input_json);
     }
 
-    fn log(self: *Self, level: @import("backends/wasmer.zig").LogLevel, comptime fmt: []const u8, args: anytype) void {
+    fn log(self: *Self, level: LogLevel, comptime fmt: []const u8, args: anytype) void {
         var buf: [256]u8 = undefined;
         const msg = std.fmt.bufPrint(&buf, fmt, args) catch return;
-        self.getWasmerBackend().opa_context.log(level, msg);
+        self.getBackend().opa_context.log(level, msg);
     }
 
     /// Looks up a builtin function name by its numeric ID.
@@ -141,9 +150,9 @@ pub const Instance = struct {
 
     /// Evaluates a policy by entrypoint ID with the given JSON input.
     pub fn evaluateById(self: *Self, entrypoint_id: u32, input_json: []const u8) ![]const u8 {
-        const wasmer_backend = self.getWasmerBackend();
-        wasmer_backend.setBuiltins(&self.builtins);
-        wasmer_backend.setOpaFunctions(
+        const backend_impl = self.getBackend();
+        backend_impl.setBuiltins(&self.builtins);
+        backend_impl.setOpaFunctions(
             self.memory_manager.opa_malloc_fn,
             self.memory_manager.opa_json_parse_fn,
             self.memory_manager.opa_json_dump_fn,
@@ -205,18 +214,18 @@ pub const Instance = struct {
     } || MemoryManager.Error;
 
     pub fn wasAborted(self: *Self) bool {
-        return self.getWasmerBackend().wasAborted();
+        return self.getBackend().wasAborted();
     }
 
     pub fn getAbortMessage(self: *Self) ?[]const u8 {
-        return self.getWasmerBackend().getAbortMessage();
+        return self.getBackend().getAbortMessage();
     }
 
     pub fn clearAbort(self: *Self) void {
-        self.getWasmerBackend().clearAbort();
+        self.getBackend().clearAbort();
     }
 
-    fn getWasmerBackend(self: *Self) *wasmer.WasmerBackend {
+    fn getBackend(self: *Self) *BackendImpl {
         return @ptrCast(@alignCast(self.policy.module.backend_ptr));
     }
 };
@@ -285,14 +294,13 @@ pub const InstancePool = struct {
 };
 
 const testing = std.testing;
-const WasmerBackend = @import("backends/wasmer.zig").WasmerBackend;
 
 test "instantiate OPA policy module" {
     const wasm_bytes = @embedFile("test_example_wasm");
-    var wasmer_backend = try WasmerBackend.init(testing.allocator);
-    defer wasmer_backend.deinit();
+    var wasm_backend = try BackendImpl.init(testing.allocator);
+    defer wasm_backend.deinit();
 
-    var b = wasmer_backend.asBackend();
+    var b = wasm_backend.asBackend();
     var policy = try Policy.load(testing.allocator, &b, wasm_bytes);
     defer policy.deinit();
 
@@ -304,10 +312,10 @@ test "instantiate OPA policy module" {
 
 test "evaluate policy - admin allowed" {
     const wasm_bytes = @embedFile("test_example_wasm");
-    var wasmer_backend = try WasmerBackend.init(testing.allocator);
-    defer wasmer_backend.deinit();
+    var wasm_backend = try BackendImpl.init(testing.allocator);
+    defer wasm_backend.deinit();
 
-    var b = wasmer_backend.asBackend();
+    var b = wasm_backend.asBackend();
     var policy = try Policy.load(testing.allocator, &b, wasm_bytes);
     defer policy.deinit();
 
@@ -322,10 +330,10 @@ test "evaluate policy - admin allowed" {
 
 test "evaluate policy - guest denied" {
     const wasm_bytes = @embedFile("test_example_wasm");
-    var wasmer_backend = try WasmerBackend.init(testing.allocator);
-    defer wasmer_backend.deinit();
+    var wasm_backend = try BackendImpl.init(testing.allocator);
+    defer wasm_backend.deinit();
 
-    var b = wasmer_backend.asBackend();
+    var b = wasm_backend.asBackend();
     var policy = try Policy.load(testing.allocator, &b, wasm_bytes);
     defer policy.deinit();
 
@@ -340,10 +348,10 @@ test "evaluate policy - guest denied" {
 
 test "policy with builtins - sprintf" {
     const wasm_bytes = @embedFile("test_builtin_wasm");
-    var wasmer_backend = try WasmerBackend.init(testing.allocator);
-    defer wasmer_backend.deinit();
+    var wasm_backend = try BackendImpl.init(testing.allocator);
+    defer wasm_backend.deinit();
 
-    var b = wasmer_backend.asBackend();
+    var b = wasm_backend.asBackend();
     var policy = try Policy.load(testing.allocator, &b, wasm_bytes);
     defer policy.deinit();
 
@@ -367,10 +375,10 @@ test "policy with builtins - sprintf" {
 
 test "instance pool acquire and release" {
     const wasm_bytes = @embedFile("test_example_wasm");
-    var wasmer_backend = try WasmerBackend.init(testing.allocator);
-    defer wasmer_backend.deinit();
+    var wasm_backend = try BackendImpl.init(testing.allocator);
+    defer wasm_backend.deinit();
 
-    var b = wasmer_backend.asBackend();
+    var b = wasm_backend.asBackend();
     var policy = try Policy.load(testing.allocator, &b, wasm_bytes);
     defer policy.deinit();
 
@@ -393,10 +401,10 @@ test "instance pool acquire and release" {
 // Regression test: OpaContext must have builtins and WASM functions connected for custom builtins to work.
 test "builtins are connected to backend context" {
     const wasm_bytes = @embedFile("test_builtin_wasm");
-    var wasmer_backend = try WasmerBackend.init(testing.allocator);
-    defer wasmer_backend.deinit();
+    var wasm_backend = try BackendImpl.init(testing.allocator);
+    defer wasm_backend.deinit();
 
-    var b = wasmer_backend.asBackend();
+    var b = wasm_backend.asBackend();
     var policy = try Policy.load(testing.allocator, &b, wasm_bytes);
     defer policy.deinit();
 
@@ -411,8 +419,8 @@ test "builtins are connected to backend context" {
         try testing.expect(res.len > 0);
     } else |_| {}
 
-    try testing.expect(wasmer_backend.opa_context.builtins != null);
-    try testing.expect(wasmer_backend.opa_context.json_dump_fn != null);
-    try testing.expect(wasmer_backend.opa_context.json_parse_fn != null);
-    try testing.expect(wasmer_backend.opa_context.malloc_fn != null);
+    try testing.expect(wasm_backend.opa_context.builtins != null);
+    try testing.expect(wasm_backend.opa_context.json_dump_fn != null);
+    try testing.expect(wasm_backend.opa_context.json_parse_fn != null);
+    try testing.expect(wasm_backend.opa_context.malloc_fn != null);
 }

src/policy.zig

@@ -126,12 +126,16 @@ fn freeStringMap(allocator: std.mem.Allocator, map: *std.StringHashMapUnmanaged(
 
 test "policy load minimal wasm" {
     const testing = std.testing;
-    const wasmer = @import("backends/wasmer.zig");
+    const options = @import("options");
+    const BackendImpl = switch (options.backend) {
+        .wasmer => @import("backends/wasmer.zig").WasmerBackend,
+        .zware => @import("backends/zware.zig").ZwareBackend,
+    };
 
     const test_wasm = @embedFile("test_add_wasm");
 
-    var wasm_backend = wasmer.WasmerBackend.init(testing.allocator) catch |err| {
-        std.debug.print("Wasmer init failed: {}\n", .{err});
+    var wasm_backend = BackendImpl.init(testing.allocator) catch |err| {
+        std.debug.print("Backend init failed: {}\n", .{err});
         return err;
     };
     defer wasm_backend.deinit();