vendor tsgo

tools/tsgo/internal/execute/incremental/incremental.go

@@ -0,0 +1,56 @@
+package incremental
+
+import (
+	"github.com/microsoft/typescript-go/internal/compiler"
+	"github.com/microsoft/typescript-go/internal/json"
+	"github.com/microsoft/typescript-go/internal/tsoptions"
+)
+
+type BuildInfoReader interface {
+	ReadBuildInfo(config *tsoptions.ParsedCommandLine) *BuildInfo
+}
+
+var _ BuildInfoReader = (*buildInfoReader)(nil)
+
+type buildInfoReader struct {
+	host compiler.CompilerHost
+}
+
+func (r *buildInfoReader) ReadBuildInfo(config *tsoptions.ParsedCommandLine) *BuildInfo {
+	buildInfoFileName := config.GetBuildInfoFileName()
+	if buildInfoFileName == "" {
+		return nil
+	}
+
+	// Read build info file
+	data, ok := r.host.FS().ReadFile(buildInfoFileName)
+	if !ok {
+		return nil
+	}
+	var buildInfo BuildInfo
+	err := json.Unmarshal([]byte(data), &buildInfo)
+	if err != nil {
+		return nil
+	}
+	return &buildInfo
+}
+
+func NewBuildInfoReader(
+	host compiler.CompilerHost,
+) BuildInfoReader {
+	return &buildInfoReader{host: host}
+}
+
+func ReadBuildInfoProgram(config *tsoptions.ParsedCommandLine, reader BuildInfoReader, host compiler.CompilerHost) *Program {
+	// Read buildInfo file
+	buildInfo := reader.ReadBuildInfo(config)
+	if buildInfo == nil || !buildInfo.IsValidVersion() || !buildInfo.IsIncremental() {
+		return nil
+	}
+
+	// Convert to information that can be used to create incremental program
+	incrementalProgram := &Program{
+		snapshot: buildInfoToSnapshot(buildInfo, config, host),
+	}
+	return incrementalProgram
+}