Add codeaction about adding 'entry' keyword

eclipse-langium · Nov 17, 2021 · f399b6c · f399b6c
1 parent 5da1cd5
commit f399b6c
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Showing 3 changed files with 27 additions and 4 deletions.
diff --git a/packages/langium/src/grammar/grammar-util.ts b/packages/langium/src/grammar/grammar-util.ts
@@ -321,9 +321,7 @@ export function getRuleType(rule: ast.AbstractRule | undefined): string {
 }
 
 export function getEntryRule(grammar: ast.Grammar): ast.ParserRule | undefined {
-    const entryRules = grammar.rules.filter(e => ast.isParserRule(e) && e.entry) as ast.ParserRule[];
-    // returns undefined if more than 1 entry rules are found
-    return entryRules.length !== 1 ? undefined : entryRules[0];
+    return grammar.rules.find(e => ast.isParserRule(e) && e.entry) as ast.ParserRule;
 }
 
 export function loadGrammar(json: string): ast.Grammar {

diff --git a/packages/langium/src/grammar/langium-grammar-code-actions.ts b/packages/langium/src/grammar/langium-grammar-code-actions.ts
@@ -38,6 +38,8 @@ export class LangiumGrammarCodeActionProvider implements CodeActionProvider {
                 return this.fixHiddenTerminals(diagnostic, document);
             case IssueCodes.UseRegexTokens:
                 return this.fixRegexTokens(diagnostic, document);
+            case IssueCodes.MakeRuleEntry:
+                return this.addEntryKeyword(diagnostic, document);
             default:
                 return undefined;
         }
@@ -67,6 +69,23 @@ export class LangiumGrammarCodeActionProvider implements CodeActionProvider {
         };
     }
 
+    private addEntryKeyword(diagnostic: Diagnostic, document: LangiumDocument): CodeAction | undefined {
+        return {
+            title: 'Add entry keyword',
+            kind: CodeActionKind.QuickFix,
+            diagnostics: [diagnostic],
+            isPreferred: true,
+            edit: {
+                changes: {
+                    [document.textDocument.uri]: [{
+                        range: {start: diagnostic.range.start, end: diagnostic.range.start},
+                        newText: 'entry '
+                    }]
+                }
+            }
+        };
+    }
+
     private fixRegexTokens(diagnostic: Diagnostic, document: LangiumDocument): CodeAction | undefined {
         const offset = document.textDocument.offsetAt(diagnostic.range.start);
         const rootCst = document.parseResult.value.$cstNode;

diff --git a/packages/langium/src/grammar/langium-grammar-validator.ts b/packages/langium/src/grammar/langium-grammar-validator.ts
@@ -52,6 +52,7 @@ export namespace IssueCodes {
     export const RuleNameUppercase = 'rule-name-uppercase';
     export const HiddenGrammarTokens = 'hidden-grammar-tokens';
     export const UseRegexTokens = 'use-regex-tokens';
+    export const MakeRuleEntry = 'make-rule-entry';
 }
 
 export class LangiumGrammarValidator {
@@ -74,7 +75,12 @@ export class LangiumGrammarValidator {
     checkEntryGrammarRule(grammar: ast.Grammar, accept: ValidationAcceptor): void {
         const entryRules = grammar.rules.filter(e => ast.isParserRule(e) && e.entry) as ast.ParserRule[];
         if (entryRules.length === 0) {
-            accept('error', 'This grammar is missing an entry parser rule.', { node: grammar, property: 'name' });
+            const possibleEntryRule = grammar.rules.find(e => ast.isParserRule(e) && !isDataTypeRule(e));
+            if (possibleEntryRule) {
+                accept('error', 'The grammar is missing an entry parser rule. This rule can be an entry one.', { node: possibleEntryRule, property: 'name', code: IssueCodes.MakeRuleEntry });
+            } else {
+                accept('error', 'This grammar is missing an entry parser rule.', { node: grammar, property: 'name' });
+            }
         } else if (entryRules.length > 1) {
             entryRules.forEach(rule => accept('error', 'The entry rule has to be unique.', { node: rule, property: 'name' }));
         } else if (isDataTypeRule(entryRules[0])) {