feat: match formatting indentation to terraform fmt (#86)

Author: OmarTawfik

.vscode/launch.json

@@ -17,10 +17,7 @@
       "request": "launch",
       "name": "Jest Current File",
       "program": "${workspaceFolder}/node_modules/.bin/jest",
-      "args": ["${relativeFile}"],
-      "console": "integratedTerminal",
-      "internalConsoleOptions": "neverOpen",
-      "disableOptimisticBPs": true,
+      "args": ["${fileBasename}"],
       "outFiles": ["${workspaceFolder}/out/**"],
       "windows": {
         "program": "${workspaceFolder}/node_modules/jest/bin/jest"

docs/formatting.md

@@ -0,0 +1,9 @@
+# Formatting Guidelines
+
+Following the ones used by `terraform fmt`:
+
+> https://www.terraform.io/docs/configuration/style.html
+
+- Indent two spaces for each nesting level.
+- Inside a block, arguments go together first, then blocks (separated by a blank line each).
+- Align their equal sign according to the longest key.

gulpfile.ts

@@ -7,6 +7,8 @@ import { BuildTasks } from "./scripts/gulp-build";
 import { LinterTasks } from "./scripts/gulp-linter";
 import { VSCodeTasks } from "./scripts/gulp-vscode";
 
+// TODO: replace all module-like files with classes
+
 // Called by debugger before launching
 gulp.task("update-vscode", gulp.series([BuildTasks.compile, VSCodeTasks.copyFiles, VSCodeTasks.generatePackageJson]));
 

src/binding/bound-nodes.ts

@@ -9,7 +9,7 @@ import {
   ObjectMemberSyntax,
   BasePropertySyntax,
 } from "../parsing/syntax-nodes";
-import { Token } from "../scanning/tokens";
+import { TokenWithTrivia } from "../scanning/tokens";
 
 export enum BoundKind {
   // Top level
@@ -147,7 +147,7 @@ export class BoundSecrets extends BaseBoundNode {
 }
 
 export class BoundStringValue extends BaseBoundNode {
-  public constructor(public readonly value: string, public readonly syntax: Token) {
+  public constructor(public readonly value: string, public readonly syntax: TokenWithTrivia) {
     super(BoundKind.StringValue);
   }
 }

src/parsing/parser.ts

@@ -3,7 +3,7 @@
  */
 
 import { DiagnosticBag } from "../util/diagnostics";
-import { Token, TokenKind, getTokenDescription } from "../scanning/tokens";
+import { Token, TokenKind, getTokenDescription, TokenWithTrivia } from "../scanning/tokens";
 import {
   DocumentSyntax,
   VersionSyntax,
@@ -22,7 +22,9 @@ interface ParseContext {
 }
 
 export function parseTokens(allTokens: ReadonlyArray<Token>, bag: DiagnosticBag): DocumentSyntax {
-  const tokens = allTokens.filter(token => token.kind !== TokenKind.Comment && token.kind !== TokenKind.Unrecognized);
+  const tokens = allTokens.filter(token => token.kind !== TokenKind.Unrecognized);
+  const commentsAfter = extractCommentsAtEndOfFile();
+
   const reportedErrors = Array<boolean>();
 
   let index = 0;
@@ -35,7 +37,18 @@ export function parseTokens(allTokens: ReadonlyArray<Token>, bag: DiagnosticBag)
     });
   }
 
-  return new DocumentSyntax(versions, blocks);
+  return new DocumentSyntax(versions, blocks, commentsAfter);
+
+  function extractCommentsAtEndOfFile(): ReadonlyArray<TokenWithTrivia> {
+    let end = tokens.length - 1;
+    while (end >= 0 && tokens[end].kind === TokenKind.Comment) {
+      end -= 1;
+    }
+
+    const result = tokens.slice(end + 1);
+    tokens.splice(end + 1);
+    return result;
+  }
 
   function parseTopLevelNode(context: ParseContext): void {
     const keywordKinds = [TokenKind.VersionKeyword, TokenKind.WorkflowKeyword, TokenKind.ActionKeyword];
@@ -66,14 +79,14 @@ export function parseTokens(allTokens: ReadonlyArray<Token>, bag: DiagnosticBag)
     }
   }
 
-  function parseVersion(version: Token, context: ParseContext): void {
+  function parseVersion(version: TokenWithTrivia, context: ParseContext): void {
     const equal = eat(context, TokenKind.Equal);
     const integer = eat(context, TokenKind.IntegerLiteral);
 
     versions.push(new VersionSyntax(version, equal, integer));
   }
 
-  function parseBlock(type: Token, context: ParseContext): void {
+  function parseBlock(type: TokenWithTrivia, context: ParseContext): void {
     const name = eat(context, TokenKind.StringLiteral);
     const openBracket = eat(context, TokenKind.LeftCurlyBracket);
 
@@ -118,7 +131,7 @@ export function parseTokens(allTokens: ReadonlyArray<Token>, bag: DiagnosticBag)
     return properties;
   }
 
-  function parseProperty(key: Token, context: ParseContext): BasePropertySyntax {
+  function parseProperty(key: TokenWithTrivia, context: ParseContext): BasePropertySyntax {
     const equal = eat(context, TokenKind.Equal);
     const valueStart = eat(context, TokenKind.StringLiteral, TokenKind.LeftCurlyBracket, TokenKind.LeftSquareBracket);
 
@@ -163,7 +176,7 @@ export function parseTokens(allTokens: ReadonlyArray<Token>, bag: DiagnosticBag)
         break;
       }
 
-      let comma: Token | undefined;
+      let comma: TokenWithTrivia | undefined;
       if (isNext(TokenKind.Comma)) {
         comma = eat(context, TokenKind.Comma);
       }
@@ -197,16 +210,37 @@ export function parseTokens(allTokens: ReadonlyArray<Token>, bag: DiagnosticBag)
     return index < tokens.length && tokens[index].kind === kind;
   }
 
-  function eat(context: ParseContext, ...expected: TokenKind[]): Token {
+  function eat(context: ParseContext, ...expected: TokenKind[]): TokenWithTrivia {
+    const commentsBefore = eatComments();
+
     while (true) {
       if (index >= tokens.length) {
-        return missingToken(expected);
+        return {
+          commentsBefore,
+          ...missingToken(expected),
+        };
       }
 
       const current = tokens[index];
       if (expected.includes(current.kind)) {
         index += 1;
-        return current;
+
+        if (index < tokens.length) {
+          const commentAfter = tokens[index];
+          if (commentAfter.kind === TokenKind.Comment && commentAfter.range.start.line === current.range.end.line) {
+            index += 1;
+            return {
+              commentsBefore,
+              ...current,
+              commentAfter,
+            };
+          }
+        }
+
+        return {
+          commentsBefore,
+          ...current,
+        };
       }
 
       let canBeHandledByParent = false;
@@ -217,7 +251,10 @@ export function parseTokens(allTokens: ReadonlyArray<Token>, bag: DiagnosticBag)
       }
 
       if (canBeHandledByParent) {
-        return missingToken(expected);
+        return {
+          commentsBefore,
+          ...missingToken(expected),
+        };
       }
 
       if (!reportedErrors[index]) {
@@ -229,6 +266,21 @@ export function parseTokens(allTokens: ReadonlyArray<Token>, bag: DiagnosticBag)
     }
   }
 
+  function eatComments(): ReadonlyArray<TokenWithTrivia> | undefined {
+    let result: TokenWithTrivia[] | undefined;
+
+    while (index < tokens.length && tokens[index].kind === TokenKind.Comment) {
+      if (!result) {
+        result = [];
+      }
+
+      result.push(tokens[index]);
+      index += 1;
+    }
+
+    return result;
+  }
+
   function missingToken(expected: TokenKind[]): Token {
     let missingIndex = index;
     const endOfFile = index >= tokens.length;

src/parsing/syntax-nodes.ts

@@ -2,7 +2,7 @@
  * Copyright 2019 Omar Tawfik. Please see LICENSE file at the root of this repository.
  */
 
-import { Token, TokenKind, getTokenDescription } from "../scanning/tokens";
+import { Token, TokenKind, getTokenDescription, TokenWithTrivia } from "../scanning/tokens";
 import { Range } from "vscode-languageserver-types";
 import { comparePositions } from "../util/ranges";
 
@@ -59,35 +59,40 @@ export class DocumentSyntax extends BaseSyntaxNode {
   public constructor(
     public readonly versions: ReadonlyArray<VersionSyntax>,
     public readonly blocks: ReadonlyArray<BlockSyntax>,
+    public readonly commentsAfter: ReadonlyArray<TokenWithTrivia>,
   ) {
     super(SyntaxKind.Document);
   }
 
-  public calculateRange(): Range {
-    return combineRange(...this.versions, ...this.blocks);
+  protected calculateRange(): Range {
+    return combineRange(...this.versions, ...this.blocks, ...this.commentsAfter);
   }
 }
 
 export class VersionSyntax extends BaseSyntaxNode {
-  public constructor(public readonly version: Token, public readonly equal: Token, public readonly integer: Token) {
+  public constructor(
+    public readonly version: TokenWithTrivia,
+    public readonly equal: TokenWithTrivia,
+    public readonly integer: TokenWithTrivia,
+  ) {
     super(SyntaxKind.Version);
     assertTokenKind(version, TokenKind.VersionKeyword);
     assertTokenKind(equal, TokenKind.Equal);
     assertTokenKind(integer, TokenKind.IntegerLiteral);
   }
 
-  public calculateRange(): Range {
+  protected calculateRange(): Range {
     return combineRange(this.version, this.equal, this.integer);
   }
 }
 
 export class BlockSyntax extends BaseSyntaxNode {
   public constructor(
-    public readonly type: Token,
-    public readonly name: Token,
-    public readonly openBracket: Token,
+    public readonly type: TokenWithTrivia,
+    public readonly name: TokenWithTrivia,
+    public readonly openBracket: TokenWithTrivia,
     public readonly properties: ReadonlyArray<BasePropertySyntax>,
-    public readonly closeBracket: Token,
+    public readonly closeBracket: TokenWithTrivia,
   ) {
     super(SyntaxKind.Block);
     assertTokenKind(type, TokenKind.ActionKeyword, TokenKind.WorkflowKeyword);
@@ -96,13 +101,17 @@ export class BlockSyntax extends BaseSyntaxNode {
     assertTokenKind(closeBracket, TokenKind.RightCurlyBracket);
   }
 
-  public calculateRange(): Range {
+  protected calculateRange(): Range {
     return combineRange(this.type, this.name, this.openBracket, ...this.properties, this.closeBracket);
   }
 }
 
 export abstract class BasePropertySyntax extends BaseSyntaxNode {
-  protected constructor(kind: SyntaxKind, public readonly key: Token, public readonly equal: Token) {
+  protected constructor(
+    kind: SyntaxKind,
+    public readonly key: TokenWithTrivia,
+    public readonly equal: TokenWithTrivia,
+  ) {
     super(kind);
     assertTokenKind(
       key,
@@ -120,73 +129,77 @@ export abstract class BasePropertySyntax extends BaseSyntaxNode {
 }
 
 export class StringPropertySyntax extends BasePropertySyntax {
-  public constructor(key: Token, equal: Token, public readonly value: Token | undefined) {
+  public constructor(key: TokenWithTrivia, equal: TokenWithTrivia, public readonly value: TokenWithTrivia | undefined) {
     super(SyntaxKind.StringProperty, key, equal);
     assertTokenKind(value, TokenKind.StringLiteral);
   }
 
-  public calculateRange(): Range {
+  protected calculateRange(): Range {
     return combineRange(this.key, this.equal, this.value);
   }
 }
 
 export class ArrayPropertySyntax extends BasePropertySyntax {
   public constructor(
-    key: Token,
-    equal: Token,
-    public readonly openBracket: Token,
+    key: TokenWithTrivia,
+    equal: TokenWithTrivia,
+    public readonly openBracket: TokenWithTrivia,
     public readonly items: ReadonlyArray<ArrayItemSyntax>,
-    public readonly closeBracket: Token,
+    public readonly closeBracket: TokenWithTrivia,
   ) {
     super(SyntaxKind.ArrayProperty, key, equal);
     assertTokenKind(openBracket, TokenKind.LeftSquareBracket);
     assertTokenKind(closeBracket, TokenKind.RightSquareBracket);
   }
 
-  public calculateRange(): Range {
+  protected calculateRange(): Range {
     return combineRange(this.openBracket, ...this.items, this.closeBracket);
   }
 }
 
 export class ArrayItemSyntax extends BaseSyntaxNode {
-  public constructor(public readonly value: Token, public readonly comma: Token | undefined) {
+  public constructor(public readonly value: TokenWithTrivia, public readonly comma: TokenWithTrivia | undefined) {
     super(SyntaxKind.ArrayItem);
     assertTokenKind(value, TokenKind.StringLiteral);
     assertTokenKind(comma, TokenKind.Comma);
   }
 
-  public calculateRange(): Range {
+  protected calculateRange(): Range {
     return combineRange(this.value, this.comma);
   }
 }
 
 export class ObjectPropertySyntax extends BasePropertySyntax {
   public constructor(
-    key: Token,
-    equal: Token,
-    public readonly openBracket: Token,
+    key: TokenWithTrivia,
+    equal: TokenWithTrivia,
+    public readonly openBracket: TokenWithTrivia,
     public readonly members: ReadonlyArray<ObjectMemberSyntax>,
-    public readonly closeBracket: Token,
+    public readonly closeBracket: TokenWithTrivia,
   ) {
     super(SyntaxKind.ObjectProperty, key, equal);
     assertTokenKind(openBracket, TokenKind.LeftCurlyBracket);
     assertTokenKind(closeBracket, TokenKind.RightCurlyBracket);
   }
 
-  public calculateRange(): Range {
+  protected calculateRange(): Range {
     return combineRange(this.openBracket, ...this.members, this.closeBracket);
   }
 }
 
 export class ObjectMemberSyntax extends BaseSyntaxNode {
-  public constructor(public readonly name: Token, public readonly equal: Token, public readonly value: Token) {
+  public constructor(
+    public readonly name: TokenWithTrivia,
+    public readonly equal: TokenWithTrivia,
+    public readonly value: TokenWithTrivia,
+  ) {
     super(SyntaxKind.ObjectMember);
     assertTokenKind(name, TokenKind.Identifier);
     assertTokenKind(equal, TokenKind.Equal);
     assertTokenKind(value, TokenKind.StringLiteral);
   }
 
-  public calculateRange(): Range {
+  protected calculateRange(): Range {
     return combineRange(this.name, this.equal, this.value);
   }
 }

src/scanning/tokens.ts

@@ -105,3 +105,8 @@ export interface Token {
   readonly range: Range;
   readonly text: string;
 }
+
+export interface TokenWithTrivia extends Token {
+  readonly commentsBefore?: ReadonlyArray<TokenWithTrivia>;
+  readonly commentAfter?: TokenWithTrivia;
+}