test: add tests on {parser,generator}Override (#12740)

packages/babel-core/test/fixtures/plugins/override/generator-override/input.js

@@ -0,0 +1 @@
+1;

packages/babel-core/test/fixtures/plugins/override/generator-override/options.json

@@ -0,0 +1,3 @@
+{
+  "plugins": ["./plugin"]
+}

packages/babel-core/test/fixtures/plugins/override/generator-override/output.js

@@ -0,0 +1 @@
+0;

packages/babel-core/test/fixtures/plugins/override/generator-override/plugin.js

@@ -0,0 +1,9 @@
+module.exports = function (api) {
+  return {
+    generatorOverride(ast, generatorOpts, code, generate) {
+      const result = generate(ast, generatorOpts, code);
+      result.code = result.code.replace("1", "0");
+      return result;
+    },
+  };
+};

packages/babel-core/test/fixtures/plugins/override/parser-override/input.js

@@ -0,0 +1 @@
+1;

packages/babel-core/test/fixtures/plugins/override/parser-override/options.json

@@ -0,0 +1,3 @@
+{
+  "plugins": ["./plugin"]
+}

packages/babel-core/test/fixtures/plugins/override/parser-override/output.js

@@ -0,0 +1 @@
+0;

packages/babel-core/test/fixtures/plugins/override/parser-override/plugin.js

@@ -0,0 +1,9 @@
+module.exports = function (api) {
+  return {
+    parserOverride(code, opts, parse) {
+      const ast = parse(code, opts);
+      ast.program.body[0].expression.value = 0;
+      return ast;
+    },
+  };
+};