feat: report errors on reserved environment variables (#34)

Author: OmarTawfik

src/binding/binder.ts

@@ -164,6 +164,11 @@ export function bindDocument(root: DocumentSyntax, bag: DiagnosticBag): BoundDoc
             bag.propertyAlreadyDefined(property.key);
           } else {
             env = new BoundEnv(bindObject(property.value), property);
+            for (const variable of env.variables.keys()) {
+              if (variable.startsWith("GITHUB_")) {
+                bag.reservedEnvironmentVariable(property.key.range);
+              }
+            }
           }
           break;
         }
@@ -247,7 +252,7 @@ export function bindDocument(root: DocumentSyntax, bag: DiagnosticBag): BoundDoc
         }
         case SyntaxKind.ObjectValue: {
           (syntax as ObjectValueSyntax).members.forEach(variable => {
-            const key = removeDoubleQuotes(variable.name.text);
+            const key = variable.name.text;
             if (map.has(key)) {
               bag.duplicateKey(key, variable.name.range);
             } else {

src/binding/bound-nodes.ts

@@ -5,22 +5,22 @@
 import { DocumentSyntax, BlockSyntax, BaseSyntaxNode, VersionSyntax, PropertySyntax } from "../parsing/syntax-nodes";
 import { filterUndefined } from "../util/array-utils";
 
-export const enum BoundKind {
+export enum BoundKind {
   // Top level
-  Document = 1,
-  Version = 2,
-  Workflow = 3,
-  Action = 4,
+  Document,
+  Version,
+  Workflow,
+  Action,
 
   // Properties
-  On = 5,
-  Resolves = 6,
-  Uses = 7,
-  Needs = 8,
-  Runs = 9,
-  Args = 10,
-  Env = 11,
-  Secrets = 12,
+  On,
+  Resolves,
+  Uses,
+  Needs,
+  Runs,
+  Args,
+  Env,
+  Secrets,
 }
 
 export abstract class BaseBoundNode<TSyntax extends BaseSyntaxNode> {

src/parsing/syntax-nodes.ts

@@ -4,25 +4,25 @@
 
 import { Token, TokenKind, getTokenDescription } from "../scanning/tokens";
 
-export const enum SyntaxKind {
+export enum SyntaxKind {
   // Top level
-  Document = 1,
-  Version = 2,
-  Block = 3,
+  Document,
+  Version,
+  Block,
 
   // Properties
-  Property = 4,
+  Property,
 
   // Strings
-  StringValue = 5,
+  StringValue,
 
   // String Arrays
-  StringArrayValue = 6,
-  StringArrayItem = 7,
+  StringArrayValue,
+  StringArrayItem,
 
   // Env Variables
-  ObjectValue = 8,
-  ObjectMember = 9,
+  ObjectValue,
+  ObjectMember,
 }
 
 function assertTokenKind(token?: Token, ...acceptedKinds: TokenKind[]): void {

src/scanning/tokens.ts

@@ -2,43 +2,43 @@
  * Copyright 2019 Omar Tawfik. Please see LICENSE file at the root of this repository.
  */
 
-export const enum TokenKind {
+export enum TokenKind {
   // Top-level keywords
-  VersionKeyword = 1,
-  WorkflowKeyword = 2,
-  ActionKeyword = 3,
+  VersionKeyword,
+  WorkflowKeyword,
+  ActionKeyword,
 
   // Bottom-level keywords
-  OnKeyword = 4,
-  ResolvesKeyword = 5,
-  UsesKeyword = 6,
-  NeedsKeyword = 7,
-  RunsKeyword = 8,
-  ArgsKeyword = 9,
-  EnvKeyword = 10,
-  SecretsKeyword = 11,
+  OnKeyword,
+  ResolvesKeyword,
+  UsesKeyword,
+  NeedsKeyword,
+  RunsKeyword,
+  ArgsKeyword,
+  EnvKeyword,
+  SecretsKeyword,
 
   // Punctuation
-  Equal = 12,
-  Comma = 13,
+  Equal,
+  Comma,
 
   // Brackets
-  LeftCurlyBracket = 14,
-  RightCurlyBracket = 15,
-  LeftSquareBracket = 16,
-  RightSquareBracket = 17,
+  LeftCurlyBracket,
+  RightCurlyBracket,
+  LeftSquareBracket,
+  RightSquareBracket,
 
   // Misc
-  Identifier = 18,
-  Comment = 19,
+  Identifier,
+  Comment,
 
   // Literals
-  IntegerLiteral = 20,
-  StringLiteral = 21,
+  IntegerLiteral,
+  StringLiteral,
 
   // Generated
-  Missing = 22,
-  Unrecognized = 23,
+  Missing,
+  Unrecognized,
 }
 
 export function getTokenDescription(kind: TokenKind): string {

src/util/diagnostics.ts

@@ -5,33 +5,34 @@
 import { TokenKind, TextRange, getTokenDescription, Token } from "../scanning/tokens";
 import { MAXIMUM_SUPPORTED_VERSION, MAXIMUM_SUPPORTED_SECRETS, MAXIMUM_SUPPORTED_ACTIONS } from "./constants";
 
-export const enum DiagnosticCode {
+export enum DiagnosticCode {
   // Scanning
-  UnrecognizedCharacter = 1,
-  UnterminatedStringLiteral = 2,
-  UnsupportedEscapeSequence = 3,
+  UnrecognizedCharacter,
+  UnterminatedStringLiteral,
+  UnsupportedEscapeSequence,
 
   // Parsing
-  MissingToken = 4,
-  UnexpectedToken = 5,
+  MissingToken,
+  UnexpectedToken,
 
   // Binding
-  MultipleVersion = 6,
-  UnrecognizedVersion = 7,
-  VersionAfterBlock = 8,
-  ValueIsNotString = 9,
-  ValueIsNotStringOrArray = 10,
-  ValueIsNotAnObject = 11,
-  PropertyAlreadyDefined = 12,
-  PropertyMustBeDefined = 13,
-  InvalidProperty = 14,
-  DuplicateKey = 15,
+  MultipleVersion,
+  UnrecognizedVersion,
+  VersionAfterBlock,
+  ValueIsNotString,
+  ValueIsNotStringOrArray,
+  ValueIsNotAnObject,
+  PropertyAlreadyDefined,
+  PropertyMustBeDefined,
+  InvalidProperty,
+  DuplicateKey,
+  ReservedEnvironmentVariable,
 
   // Analysis:
-  TooManySecrets = 16,
-  DuplicateSecrets = 17,
-  TooManyActions = 18,
-  DuplicateActions = 19,
+  TooManySecrets,
+  DuplicateSecrets,
+  TooManyActions,
+  DuplicateActions,
 }
 
 export interface Diagnostic {
@@ -175,6 +176,14 @@ export class DiagnosticBag {
     });
   }
 
+  public reservedEnvironmentVariable(range: TextRange): void {
+    this.items.push({
+      range,
+      code: DiagnosticCode.ReservedEnvironmentVariable,
+      message: `Environment variables starting with 'GITHUB_' are reserved.`,
+    });
+  }
+
   public tooManySecrets(range: TextRange): void {
     this.items.push({
       range,

test/binding-errors.spec.ts

@@ -223,6 +223,28 @@ ERROR: Value must be an object.
   5 | }
   6 | 
 "
+`);
+  });
+
+  it("reports errors on reserved environment variables", () => {
+    expectDiagnostics(`
+action "x" {
+  uses = "./ci"
+  env = {
+    GITHUB_ACTION = "1"
+    GITHUBNOUNDERSCORE = "2"
+    SOMETHING_ELSE = "3"
+  }
+}`).toMatchInlineSnapshot(`
+"
+ERROR: Environment variables starting with 'GITHUB_' are reserved.
+  2 | action \\"x\\" {
+  3 |   uses = \\"./ci\\"
+  4 |   env = {
+    |   ^^^
+  5 |     GITHUB_ACTION = \\"1\\"
+  6 |     GITHUBNOUNDERSCORE = \\"2\\"
+"
 `);
   });
 });

tsconfig.json

@@ -8,6 +8,9 @@
     "types": ["jest"],
     "lib": [],
 
+    // Features
+    "downlevelIteration": true,
+
     // Output files
     "declaration": true,
     "sourceMap": true,