vendor tsgo

tools/tsgo/internal/transformers/estransforms/classthis.go

@@ -0,0 +1,28 @@
+package estransforms
+
+import (
+	"github.com/microsoft/typescript-go/internal/ast"
+	"github.com/microsoft/typescript-go/internal/printer"
+)
+
+// Gets whether a node is a `static {}` block containing only a single assignment of the static `this` to the `_classThis`
+// (or similar) variable stored in the `classthis` property of the block's `EmitNode`.
+func isClassThisAssignmentBlock(emitContext *printer.EmitContext, node *ast.Node) bool {
+	if ast.IsClassStaticBlockDeclaration(node) {
+		n := node.AsClassStaticBlockDeclaration()
+		body := n.Body.AsBlock()
+		if len(body.Statements.Nodes) == 1 {
+			statement := body.Statements.Nodes[0]
+			if ast.IsExpressionStatement(statement) {
+				expression := statement.Expression()
+				if ast.IsAssignmentExpression(expression, true /*excludeCompoundAssignment*/) {
+					binary := expression.AsBinaryExpression()
+					return ast.IsIdentifier(binary.Left) &&
+						emitContext.ClassThis(node) == binary.Left &&
+						binary.Right.Kind == ast.KindThisKeyword
+				}
+			}
+		}
+	}
+	return false
+}