feat: add go local provider

.gitignore

@@ -1,11 +1,17 @@
 # Ignore generated protobuf Java sources vendored during local build
 openfeature-provider/java/src/main/java/com/spotify/confidence/wasm/Messages.java
+
+# Ignore compiled Go binaries
+openfeature-provider/go/demo/demo
 .DS_Store
 *.stamp
 .idea/
 .java-version
 
 target/
+# Ignore WASM in root wasm/ directory (build artifact)
 wasm/confidence_resolver.wasm
+# But DO track WASM embedded in Go provider (committed for go:embed)
+!openfeature-provider/go/wasm/confidence_resolver.wasm
 
 

.release-please-manifest.json

@@ -1 +1,9 @@
-{"confidence-resolver":"0.6.0","confidence-cloudflare-resolver":"0.3.0","wasm-msg":"0.2.1","wasm/rust-guest":"0.1.9","openfeature-provider/java":"0.7.2","openfeature-provider/js":"0.1.1"}
+{
+  "confidence-resolver": "0.6.0",
+  "confidence-cloudflare-resolver": "0.3.0",
+  "wasm-msg": "0.2.1",
+  "wasm/rust-guest": "0.1.9",
+  "openfeature-provider/java": "0.7.2",
+  "openfeature-provider/js": "0.1.1",
+  "openfeature-provider/go": "0.0.0"
+}

Cargo.toml

@@ -7,7 +7,8 @@ members = [
     "confidence-resolver",
     "confidence-cloudflare-resolver",
     "openfeature-provider/java",
-    "openfeature-provider/js"
+    "openfeature-provider/js",
+    "openfeature-provider/go"
 ]
 
 # Exclude the Java provider from default workspace builds (cargo build --workspace)

Dockerfile

@@ -47,6 +47,7 @@ COPY wasm-msg/Cargo.toml ./wasm-msg/
 COPY wasm/rust-guest/Cargo.toml ./wasm/rust-guest/
 COPY openfeature-provider/java/Cargo.toml ./openfeature-provider/java/
 COPY openfeature-provider/js/Cargo.toml ./openfeature-provider/js/
+COPY openfeature-provider/go/Cargo.toml ./openfeature-provider/go/
 
 # Copy proto files (needed by build.rs)
 COPY confidence-resolver/protos ./confidence-resolver/protos/
@@ -99,6 +100,7 @@ COPY wasm/rust-guest/ ./wasm/rust-guest/
 COPY wasm/proto/ ./wasm/proto/
 COPY openfeature-provider/java/Cargo.toml ./openfeature-provider/java/
 COPY openfeature-provider/js/Cargo.toml ./openfeature-provider/js/
+COPY openfeature-provider/go/Cargo.toml ./openfeature-provider/go/
 
 # Touch files to ensure rebuild (dependencies are cached)
 RUN find . -type f -name "*.rs" -exec touch {} +
@@ -152,6 +154,7 @@ COPY wasm/rust-guest/ ./wasm/rust-guest/
 COPY wasm/proto/ ./wasm/proto/
 COPY openfeature-provider/java/Cargo.toml ./openfeature-provider/java/
 COPY openfeature-provider/js/Cargo.toml ./openfeature-provider/js/
+COPY openfeature-provider/go/Cargo.toml ./openfeature-provider/go/
 
 # Copy data directory (needed by confidence-cloudflare-resolver include_str! macros)
 COPY data/ ./data/
@@ -437,6 +440,92 @@ FROM scratch AS openfeature-provider-js.artifact
 
 COPY --from=openfeature-provider-js.pack /app/package.tgz /package.tgz
 
+# ==============================================================================
+# OpenFeature Provider (Go) - Build and test
+# ==============================================================================
+FROM golang:1.24-alpine AS openfeature-provider-go-base
+
+# Install make (needed for Makefile targets)
+RUN apk add --no-cache make
+
+WORKDIR /app
+
+# Copy go.mod for dependency caching
+COPY openfeature-provider/go/go.mod openfeature-provider/go/go.sum ./
+COPY openfeature-provider/go/Makefile ./
+
+# Download Go dependencies (this layer will be cached)
+RUN go mod download
+
+# Copy pre-generated protobuf files
+COPY openfeature-provider/go/proto ./proto/
+
+# Copy WASM module to embedded location
+COPY --from=wasm-rust-guest.artifact /confidence_resolver.wasm ./wasm/confidence_resolver.wasm
+
+# Set environment variable
+ENV IN_DOCKER_BUILD=1
+
+# Copy source code
+COPY openfeature-provider/go/*.go ./
+
+# ==============================================================================
+# Validate WASM sync for Go Provider
+# ==============================================================================
+FROM alpine:3.22 AS openfeature-provider-go.validate-wasm
+
+# Install diffutils for cmp command
+RUN apk add --no-cache diffutils
+
+# Copy built WASM from artifact
+COPY --from=wasm-rust-guest.artifact /confidence_resolver.wasm /built/confidence_resolver.wasm
+
+# Copy committed WASM from source
+COPY openfeature-provider/go/wasm/confidence_resolver.wasm /committed/confidence_resolver.wasm
+
+# Compare files
+RUN set -e; \
+    echo "Validating WASM sync for Go provider..."; \
+    if ! cmp -s /built/confidence_resolver.wasm /committed/confidence_resolver.wasm; then \
+      echo ""; \
+      echo "❌ ERROR: WASM files are out of sync!"; \
+      echo ""; \
+      echo "The WASM file in openfeature-provider/go/wasm/ doesn't match the built version."; \
+      echo ""; \
+      echo "To fix (using Docker to ensure correct dependencies):"; \
+      echo "  docker build --target wasm-rust-guest.artifact --output type=local,dest=. ."; \
+      echo "  cp confidence_resolver.wasm openfeature-provider/go/wasm/"; \
+      echo "  git add openfeature-provider/go/wasm/confidence_resolver.wasm"; \
+      echo "  git commit -m 'chore: sync WASM module for Go provider'"; \
+      echo ""; \
+      echo "Or use the Makefile target:"; \
+      echo "  make sync-wasm-go"; \
+      echo ""; \
+      exit 1; \
+    fi; \
+    echo "✅ WASM files are in sync"
+
+# ==============================================================================
+# Test OpenFeature Provider (Go)
+# ==============================================================================
+FROM openfeature-provider-go-base AS openfeature-provider-go.test
+
+RUN make test
+
+# ==============================================================================
+# Lint OpenFeature Provider (Go)
+# ==============================================================================
+FROM openfeature-provider-go-base AS openfeature-provider-go.lint
+
+RUN make lint
+
+# ==============================================================================
+# Build OpenFeature Provider (Go)
+# ==============================================================================
+FROM openfeature-provider-go-base AS openfeature-provider-go.build
+
+RUN make build
+
 # ==============================================================================
 # OpenFeature Provider (Java) - Build and test
 # ==============================================================================
@@ -511,19 +600,25 @@ COPY --from=wasm-msg.test /workspace/Cargo.toml /markers/test-wasm-msg
 COPY --from=openfeature-provider-js.test /app/package.json /markers/test-openfeature-js
 COPY --from=openfeature-provider-js.test_e2e /app/package.json /markers/test-openfeature-js-e2e
 COPY --from=openfeature-provider-java.test /app/pom.xml /markers/test-openfeature-java
+COPY --from=openfeature-provider-go.test /app/go.mod /markers/test-openfeature-go
+
+# Force validation stages to run
+COPY --from=openfeature-provider-go.validate-wasm /built/confidence_resolver.wasm /markers/validate-wasm-go
 
 # Force integration test stages to run (host examples)
 COPY --from=node-host.test /app/package.json /markers/integration-node
 COPY --from=java-host.test /app/pom.xml /markers/integration-java
 COPY --from=go-host.test /app/go.mod /markers/integration-go
 COPY --from=python-host.test /app/Makefile /markers/integration-python
 
-# Force lint stages to run by copying marker files  
+# Force lint stages to run by copying marker files
 COPY --from=confidence-resolver.lint /workspace/Cargo.toml /markers/lint-resolver
 COPY --from=wasm-msg.lint /workspace/Cargo.toml /markers/lint-wasm-msg
 COPY --from=wasm-rust-guest.lint /workspace/Cargo.toml /markers/lint-guest
+COPY --from=openfeature-provider-go.lint /app/go.mod /markers/lint-openfeature-go
+COPY --from=confidence-cloudflare-resolver.lint /workspace/Cargo.toml /markers/lint-cloudflare
 
 # Force build stages to run
 COPY --from=openfeature-provider-js.build /app/dist/index.node.js /artifacts/openfeature-js/
 COPY --from=openfeature-provider-java.build /app/target/*.jar /artifacts/openfeature-java/
-COPY --from=confidence-cloudflare-resolver.lint /workspace/Cargo.toml /markers/lint-cloudflare
+COPY --from=openfeature-provider-go.build /app/.build.stamp /artifacts/openfeature-go/

Makefile

@@ -13,11 +13,27 @@ wasm/confidence_resolver.wasm: $(TARGET_WASM)
 	@cp -p $(TARGET_WASM) $@
 	@echo "WASM size: $$(ls -lh $@ | awk '{print $$5}')"
 
+# Sync WASM to Go provider using Docker to ensure correct toolchain
+.PHONY: sync-wasm-go
+sync-wasm-go:
+	@echo "Building WASM with Docker to ensure correct dependencies..."
+	@docker build --target wasm-rust-guest.artifact --output type=local,dest=. .
+	@echo "Copying to Go provider embedded location..."
+	@mkdir -p openfeature-provider/go/wasm
+	@cp confidence_resolver.wasm openfeature-provider/go/wasm/
+	@rm confidence_resolver.wasm
+	@echo "✅ WASM synced to openfeature-provider/go/wasm/"
+	@echo ""
+	@echo "Don't forget to commit the change:"
+	@echo "  git add openfeature-provider/go/wasm/confidence_resolver.wasm"
+	@echo "  git commit -m 'chore: sync WASM module for Go provider'"
+
 test:
 	$(MAKE) -C confidence-resolver test
 	$(MAKE) -C wasm-msg test
 	$(MAKE) -C openfeature-provider/js test
 	$(MAKE) -C openfeature-provider/java test
+	$(MAKE) -C openfeature-provider/go test
 
 integration-test:
 	$(MAKE) -C wasm/node-host run
@@ -32,11 +48,13 @@ lint:
 	$(MAKE) -C wasm-msg lint
 	$(MAKE) -C wasm/rust-guest lint
 	$(MAKE) -C confidence-cloudflare-resolver lint
+	$(MAKE) -C openfeature-provider/go lint
 	cargo fmt --check -p wasm-msg -p rust-guest -p confidence_resolver -p confidence-cloudflare-resolver
 
 build: wasm/confidence_resolver.wasm
 	$(MAKE) -C openfeature-provider/js build
 	$(MAKE) -C openfeature-provider/java build
+	$(MAKE) -C openfeature-provider/go build
 
 all: lint test build
 	@echo "✅ All checks passed!"
@@ -49,5 +67,6 @@ clean:
 	$(MAKE) -C wasm/python-host clean
 	$(MAKE) -C openfeature-provider/js clean
 	$(MAKE) -C openfeature-provider/java clean
+	$(MAKE) -C openfeature-provider/go clean
 
 .DEFAULT_GOAL := all

openfeature-provider/go/CHANGELOG.md

@@ -0,0 +1,2 @@
+# Changelog
+

openfeature-provider/go/Cargo.toml

@@ -0,0 +1,20 @@
+[package]
+name = "openfeature-provider-go"
+version = "0.0.0"
+edition = "2021"
+publish = false
+
+# This is a dummy Cargo.toml to enable cargo-workspace plugin tracking
+# in release-please. The actual package is built with Go (go.mod).
+# This package depends on rust-guest's WASM output.
+#
+# Note: This dummy package is never actually built - it exists solely for
+# release-please dependency tracking via the cargo-workspace plugin.
+
+[lib]
+# Dummy library with no source - cargo won't try to build it
+path = "Cargo.toml"
+crate-type = []
+
+[dependencies]
+rust-guest = { path = "../../wasm/rust-guest", version = "0.1.9" }

openfeature-provider/go/Makefile

@@ -0,0 +1,59 @@
+# openfeature-provider/go Makefile
+# Go OpenFeature local provider
+
+ROOT := $(realpath $(CURDIR)/../..)
+
+# Stamps and directories
+BUILD_STAMP := .build.stamp
+PROTO_DIR := proto
+WASM_ARTIFACT := $(ROOT)/wasm/confidence_resolver.wasm
+
+# Source files
+GO_SRC := $(shell find . -name '*.go' -not -path './proto/*' -not -path './demo/*')
+PROTO_GEN := $(shell find $(PROTO_DIR) -name '*.pb.go' 2>/dev/null)
+
+.PHONY: install build test lint clean proto
+
+# Always build wasm if not in docker
+ifneq ($(IN_DOCKER_BUILD),1)
+.PHONY: build-wasm
+build-wasm:
+	@$(MAKE) -C $(ROOT) wasm/confidence_resolver.wasm
+$(BUILD_STAMP): | build-wasm
+endif
+
+# Install Go dependencies
+install:
+	go mod download
+	go mod verify
+
+# Generate protobuf files
+proto:
+	./scripts/generate_proto.sh
+
+# Build (compile check)
+$(BUILD_STAMP): go.mod go.sum $(GO_SRC) $(PROTO_GEN)
+	go build ./...
+	@touch $@
+
+build: $(BUILD_STAMP)
+
+# Run tests
+test: $(BUILD_STAMP)
+	go test -v ./...
+
+# Lint using gofmt and go vet
+lint:
+	@echo "Checking gofmt..."
+	@test -z "$$(gofmt -l . | grep -v '^proto/' | tee /dev/stderr)" || (echo "Files need formatting. Run: gofmt -w ." && exit 1)
+	@echo "Running go vet..."
+	@go vet ./...
+	@echo "✅ Lint passed"
+
+# Clean build artifacts
+clean:
+	rm -rf $(PROTO_DIR)
+	rm -f $(BUILD_STAMP)
+	go clean -cache -testcache -modcache
+
+.DEFAULT_GOAL := build

openfeature-provider/go/confidence/proto

@@ -0,0 +1 @@
+../proto