Extract code generation logic into internal/api package

internal/api/api.go

@@ -0,0 +1,11 @@
+// Package api is intended to be the future public API for sqlc.
+//
+// The shape of this package is inspired by esbuild's Build API
+// (https://pkg.go.dev/github.com/evanw/esbuild/pkg/api#hdr-Build_API): a small
+// surface area of options structs and result structs that lets callers drive
+// sqlc programmatically without going through the CLI.
+//
+// Today the package lives under internal/ while the API stabilises. Once the
+// surface settles it is expected to graduate to pkg/api so it can be imported
+// by external Go programs.
+package api

internal/api/codegen.go

@@ -0,0 +1,108 @@
+package api
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"runtime/trace"
+
+	"google.golang.org/grpc"
+
+	"github.com/sqlc-dev/sqlc/internal/codegen/golang"
+	genjson "github.com/sqlc-dev/sqlc/internal/codegen/json"
+	"github.com/sqlc-dev/sqlc/internal/compiler"
+	"github.com/sqlc-dev/sqlc/internal/config"
+	"github.com/sqlc-dev/sqlc/internal/config/convert"
+	"github.com/sqlc-dev/sqlc/internal/ext"
+	"github.com/sqlc-dev/sqlc/internal/ext/process"
+	"github.com/sqlc-dev/sqlc/internal/ext/wasm"
+	"github.com/sqlc-dev/sqlc/internal/plugin"
+)
+
+func findPlugin(conf config.Config, name string) (*config.Plugin, error) {
+	for _, plug := range conf.Plugins {
+		if plug.Name == name {
+			return &plug, nil
+		}
+	}
+	return nil, fmt.Errorf("plugin not found")
+}
+
+func codegen(ctx context.Context, combo config.CombinedSettings, sql outputPair, result *compiler.Result) (string, *plugin.GenerateResponse, error) {
+	defer trace.StartRegion(ctx, "codegen").End()
+	req := codeGenRequest(result, combo)
+	var handler grpc.ClientConnInterface
+	var out string
+	switch {
+	case sql.Plugin != nil:
+		out = sql.Plugin.Out
+		plug, err := findPlugin(combo.Global, sql.Plugin.Plugin)
+		if err != nil {
+			return "", nil, fmt.Errorf("plugin not found: %s", err)
+		}
+
+		switch {
+		case plug.Process != nil:
+			handler = &process.Runner{
+				Cmd:    plug.Process.Cmd,
+				Env:    plug.Env,
+				Format: plug.Process.Format,
+			}
+		case plug.WASM != nil:
+			handler = &wasm.Runner{
+				URL:    plug.WASM.URL,
+				SHA256: plug.WASM.SHA256,
+				Env:    plug.Env,
+			}
+		default:
+			return "", nil, fmt.Errorf("unsupported plugin type")
+		}
+
+		opts, err := convert.YAMLtoJSON(sql.Plugin.Options)
+		if err != nil {
+			return "", nil, fmt.Errorf("invalid plugin options: %w", err)
+		}
+		req.PluginOptions = opts
+
+		global, found := combo.Global.Options[plug.Name]
+		if found {
+			opts, err := convert.YAMLtoJSON(global)
+			if err != nil {
+				return "", nil, fmt.Errorf("invalid global options: %w", err)
+			}
+			req.GlobalOptions = opts
+		}
+
+	case sql.Gen.Go != nil:
+		out = combo.Go.Out
+		handler = ext.HandleFunc(golang.Generate)
+		opts, err := json.Marshal(sql.Gen.Go)
+		if err != nil {
+			return "", nil, fmt.Errorf("opts marshal failed: %w", err)
+		}
+		req.PluginOptions = opts
+
+		if combo.Global.Overrides.Go != nil {
+			opts, err := json.Marshal(combo.Global.Overrides.Go)
+			if err != nil {
+				return "", nil, fmt.Errorf("opts marshal failed: %w", err)
+			}
+			req.GlobalOptions = opts
+		}
+
+	case sql.Gen.JSON != nil:
+		out = combo.JSON.Out
+		handler = ext.HandleFunc(genjson.Generate)
+		opts, err := json.Marshal(sql.Gen.JSON)
+		if err != nil {
+			return "", nil, fmt.Errorf("opts marshal failed: %w", err)
+		}
+		req.PluginOptions = opts
+
+	default:
+		return "", nil, fmt.Errorf("missing language backend")
+	}
+	client := plugin.NewCodegenServiceClient(handler)
+	resp, err := client.Generate(ctx, req)
+	return out, resp, err
+}

internal/api/diff.go

@@ -0,0 +1,107 @@
+package api
+
+import (
+	"bufio"
+	"bytes"
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"runtime/trace"
+	"sort"
+
+	"github.com/cubicdaiya/gonp"
+)
+
+func writeFiles(ctx context.Context, files map[string]string, stderr io.Writer) error {
+	defer trace.StartRegion(ctx, "writefiles").End()
+	for filename, source := range files {
+		if err := os.MkdirAll(filepath.Dir(filename), 0755); err != nil {
+			fmt.Fprintf(stderr, "%s: %s\n", filename, err)
+			return err
+		}
+		if err := os.WriteFile(filename, []byte(source), 0644); err != nil {
+			fmt.Fprintf(stderr, "%s: %s\n", filename, err)
+			return err
+		}
+	}
+	return nil
+}
+
+func diffFiles(ctx context.Context, files map[string]string, stderr io.Writer) error {
+	defer trace.StartRegion(ctx, "checkfiles").End()
+	var errored bool
+
+	wd, _ := os.Getwd()
+
+	keys := make([]string, 0, len(files))
+	for k := range files {
+		keys = append(keys, k)
+	}
+	sort.Strings(keys)
+
+	for _, filename := range keys {
+		source := files[filename]
+		if _, err := os.Stat(filename); errors.Is(err, os.ErrNotExist) {
+			errored = true
+			continue
+		}
+		existing, err := os.ReadFile(filename)
+		if err != nil {
+			errored = true
+			fmt.Fprintf(stderr, "%s: %s\n", filename, err)
+			continue
+		}
+		d := gonp.New(getLines(existing), getLines([]byte(source)))
+		d.Compose()
+		uniHunks := filterHunks(d.UnifiedHunks())
+
+		if len(uniHunks) > 0 {
+			errored = true
+			label := filename
+			if wd != "" {
+				if rel, err := filepath.Rel(wd, filename); err == nil {
+					label = "/" + rel
+				}
+			}
+			fmt.Fprintf(stderr, "--- a%s\n", label)
+			fmt.Fprintf(stderr, "+++ b%s\n", label)
+			d.FprintUniHunks(stderr, uniHunks)
+		}
+	}
+	if errored {
+		return errors.New("diff found")
+	}
+	return nil
+}
+
+func getLines(f []byte) []string {
+	fp := bytes.NewReader(f)
+	scanner := bufio.NewScanner(fp)
+	lines := make([]string, 0)
+	for scanner.Scan() {
+		lines = append(lines, scanner.Text())
+	}
+	return lines
+}
+
+func filterHunks[T gonp.Elem](uniHunks []gonp.UniHunk[T]) []gonp.UniHunk[T] {
+	var out []gonp.UniHunk[T]
+	for i, uniHunk := range uniHunks {
+		var changed bool
+		for _, e := range uniHunk.GetChanges() {
+			switch e.GetType() {
+			case gonp.SesDelete:
+				changed = true
+			case gonp.SesAdd:
+				changed = true
+			}
+		}
+		if changed {
+			out = append(out, uniHunks[i])
+		}
+	}
+	return out
+}