[Master] Fix 15179 missing comment in switch case clause (#16033)

* Fix emit comments after switch case clause

* Update baselines

* Add new tests and baselines

src/compiler/emitter.ts

@@ -2021,6 +2021,22 @@ namespace ts {
                     rangeStartPositionsAreOnSameLine(parentNode, statements[0], currentSourceFile)
                 );
 
+            // e.g:
+            //      case 0: // Zero
+            //      case 1: // One
+            //      case 2: // two
+            //          return "hi";
+            // If there is no statements, emitNodeWithComments of the parentNode which is caseClause will take care of trailing comment.
+            // So in example above, comment "// Zero" and "// One" will be emit in emitTrailingComments in emitNodeWithComments.
+            // However, for "case 2", because parentNode which is caseClause has an "end" property to be end of the statements (in this case return statement)
+            // comment "// two" will not be emitted in emitNodeWithComments.
+            // Therefore, we have to do the check here to emit such comment.
+            if (statements.length > 0) {
+                // We use emitTrailingCommentsOfPosition instead of emitLeadingCommentsOfPosition because leading comments is defined as comments before the node after newline character separating it from previous line
+                // Note: we can't use parentNode.end as such position includes statements.
+                emitTrailingCommentsOfPosition(statements.pos);
+            }
+
             if (emitAsSingleStatement) {
                 write(" ");
                 emit(statements[0]);

tests/baselines/reference/commentsAfterCaseClauses1.js

@@ -0,0 +1,31 @@
+//// [commentsAfterCaseClauses1.ts]
+function getSecurity(level) {
+    switch(level){
+        case 0: // Zero
+        case 1: // one
+        case 2: // two
+            return "Hi";
+        case 3: // three
+        case 4   : // four
+            return "hello";
+        case 5: // five
+        default:  // default
+            return "world";
+    }
+}
+
+//// [commentsAfterCaseClauses1.js]
+function getSecurity(level) {
+    switch (level) {
+        case 0: // Zero
+        case 1: // one
+        case 2:// two
+            return "Hi";
+        case 3: // three
+        case 4:// four
+            return "hello";
+        case 5: // five
+        default:// default
+            return "world";
+    }
+}

tests/baselines/reference/commentsAfterCaseClauses1.symbols

@@ -0,0 +1,20 @@
+=== tests/cases/compiler/commentsAfterCaseClauses1.ts ===
+function getSecurity(level) {
+>getSecurity : Symbol(getSecurity, Decl(commentsAfterCaseClauses1.ts, 0, 0))
+>level : Symbol(level, Decl(commentsAfterCaseClauses1.ts, 0, 21))
+
+    switch(level){
+>level : Symbol(level, Decl(commentsAfterCaseClauses1.ts, 0, 21))
+
+        case 0: // Zero
+        case 1: // one
+        case 2: // two
+            return "Hi";
+        case 3: // three
+        case 4   : // four
+            return "hello";
+        case 5: // five
+        default:  // default
+            return "world";
+    }
+}

tests/baselines/reference/commentsAfterCaseClauses1.types

@@ -0,0 +1,37 @@
+=== tests/cases/compiler/commentsAfterCaseClauses1.ts ===
+function getSecurity(level) {
+>getSecurity : (level: any) => "Hi" | "hello" | "world"
+>level : any
+
+    switch(level){
+>level : any
+
+        case 0: // Zero
+>0 : 0
+
+        case 1: // one
+>1 : 1
+
+        case 2: // two
+>2 : 2
+
+            return "Hi";
+>"Hi" : "Hi"
+
+        case 3: // three
+>3 : 3
+
+        case 4   : // four
+>4 : 4
+
+            return "hello";
+>"hello" : "hello"
+
+        case 5: // five
+>5 : 5
+
+        default:  // default
+            return "world";
+>"world" : "world"
+    }
+}

tests/baselines/reference/commentsAfterCaseClauses2.js

@@ -0,0 +1,36 @@
+//// [commentsAfterCaseClauses2.ts]
+function getSecurity(level) {
+    switch(level){
+        case 0: // Zero
+        case 1: // one
+        case 2: // two
+            // Leading comments
+            return "Hi";
+        case 3: // three
+        case 4: // four
+            return "hello";
+        case 5: // five
+        default: // default
+            return "world";
+        // Comment After
+    } /*Comment 1*/ // Comment After 1
+    // Comment After 2
+}
+
+//// [commentsAfterCaseClauses2.js]
+function getSecurity(level) {
+    switch (level) {
+        case 0: // Zero
+        case 1: // one
+        case 2:// two
+            // Leading comments
+            return "Hi";
+        case 3: // three
+        case 4:// four
+            return "hello";
+        case 5: // five
+        default:// default
+            return "world";
+    } /*Comment 1*/ // Comment After 1
+    // Comment After 2
+}

tests/baselines/reference/commentsAfterCaseClauses2.symbols

@@ -0,0 +1,23 @@
+=== tests/cases/compiler/commentsAfterCaseClauses2.ts ===
+function getSecurity(level) {
+>getSecurity : Symbol(getSecurity, Decl(commentsAfterCaseClauses2.ts, 0, 0))
+>level : Symbol(level, Decl(commentsAfterCaseClauses2.ts, 0, 21))
+
+    switch(level){
+>level : Symbol(level, Decl(commentsAfterCaseClauses2.ts, 0, 21))
+
+        case 0: // Zero
+        case 1: // one
+        case 2: // two
+            // Leading comments
+            return "Hi";
+        case 3: // three
+        case 4: // four
+            return "hello";
+        case 5: // five
+        default: // default
+            return "world";
+        // Comment After
+    } /*Comment 1*/ // Comment After 1
+    // Comment After 2
+}

tests/baselines/reference/commentsAfterCaseClauses2.types

@@ -0,0 +1,41 @@
+=== tests/cases/compiler/commentsAfterCaseClauses2.ts ===
+function getSecurity(level) {
+>getSecurity : (level: any) => "Hi" | "hello" | "world"
+>level : any
+
+    switch(level){
+>level : any
+
+        case 0: // Zero
+>0 : 0
+
+        case 1: // one
+>1 : 1
+
+        case 2: // two
+>2 : 2
+
+            // Leading comments
+            return "Hi";
+>"Hi" : "Hi"
+
+        case 3: // three
+>3 : 3
+
+        case 4: // four
+>4 : 4
+
+            return "hello";
+>"hello" : "hello"
+
+        case 5: // five
+>5 : 5
+
+        default: // default
+            return "world";
+>"world" : "world"
+
+        // Comment After
+    } /*Comment 1*/ // Comment After 1
+    // Comment After 2
+}

tests/baselines/reference/commentsAfterCaseClauses3.js

@@ -0,0 +1,34 @@
+//// [commentsAfterCaseClauses3.ts]
+function getSecurity(level) {
+    switch(level){
+        case 0: /*Zero*/
+        case 1: /*One*/ 
+        case 2: /*two*/
+            // Leading comments
+            return "Hi";
+        case 3: /*three*/
+        case 4: /*four*/
+            return "hello";
+        case 5: /*five*/
+        default:  /*six*/
+            return "world";
+    }
+    
+}
+
+//// [commentsAfterCaseClauses3.js]
+function getSecurity(level) {
+    switch (level) {
+        case 0: /*Zero*/
+        case 1: /*One*/
+        case 2:/*two*/ 
+            // Leading comments
+            return "Hi";
+        case 3: /*three*/
+        case 4:/*four*/ 
+            return "hello";
+        case 5: /*five*/
+        default:/*six*/ 
+            return "world";
+    }
+}

tests/baselines/reference/commentsAfterCaseClauses3.symbols

@@ -0,0 +1,22 @@
+=== tests/cases/compiler/commentsAfterCaseClauses3.ts ===
+function getSecurity(level) {
+>getSecurity : Symbol(getSecurity, Decl(commentsAfterCaseClauses3.ts, 0, 0))
+>level : Symbol(level, Decl(commentsAfterCaseClauses3.ts, 0, 21))
+
+    switch(level){
+>level : Symbol(level, Decl(commentsAfterCaseClauses3.ts, 0, 21))
+
+        case 0: /*Zero*/
+        case 1: /*One*/ 
+        case 2: /*two*/
+            // Leading comments
+            return "Hi";
+        case 3: /*three*/
+        case 4: /*four*/
+            return "hello";
+        case 5: /*five*/
+        default:  /*six*/
+            return "world";
+    }
+    
+}

tests/baselines/reference/commentsAfterCaseClauses3.types

@@ -0,0 +1,39 @@
+=== tests/cases/compiler/commentsAfterCaseClauses3.ts ===
+function getSecurity(level) {
+>getSecurity : (level: any) => "Hi" | "hello" | "world"
+>level : any
+
+    switch(level){
+>level : any
+
+        case 0: /*Zero*/
+>0 : 0
+
+        case 1: /*One*/ 
+>1 : 1
+
+        case 2: /*two*/
+>2 : 2
+
+            // Leading comments
+            return "Hi";
+>"Hi" : "Hi"
+
+        case 3: /*three*/
+>3 : 3
+
+        case 4: /*four*/
+>4 : 4
+
+            return "hello";
+>"hello" : "hello"
+
+        case 5: /*five*/
+>5 : 5
+
+        default:  /*six*/
+            return "world";
+>"world" : "world"
+    }
+    
+}

tests/baselines/reference/parserRealSource1.js

@@ -247,28 +247,28 @@ var TypeScript;
         var addChar = function (index) {
             var ch = value.charCodeAt(index);
             switch (ch) {
-                case 0x09:
+                case 0x09:// tab
                     result += "\\t";
                     break;
-                case 0x0a:
+                case 0x0a:// line feed
                     result += "\\n";
                     break;
-                case 0x0b:
+                case 0x0b:// vertical tab
                     result += "\\v";
                     break;
-                case 0x0c:
+                case 0x0c:// form feed
                     result += "\\f";
                     break;
-                case 0x0d:
+                case 0x0d:// carriage return
                     result += "\\r";
                     break;
-                case 0x22:
+                case 0x22:// double quote
                     result += "\\\"";
                     break;
-                case 0x27:
+                case 0x27:// single quote
                     result += "\\\'";
                     break;
-                case 0x5c:
+                case 0x5c:// Backslash
                     result += "\\";
                     break;
                 default:

tests/baselines/reference/parserindenter.js

@@ -912,20 +912,20 @@ var Formatting;
         Indenter.prototype.GetSpecialCaseIndentation = function (token, node) {
             var indentationInfo = null;
             switch (token.Token) {
-                case AuthorTokenKind.atkLCurly:
+                case AuthorTokenKind.atkLCurly:// { is not part of the tree
                     indentationInfo = this.GetSpecialCaseIndentationForLCurly(node);
                     return indentationInfo;
                 case AuthorTokenKind.atkElse: // else is not part of the tree
-                case AuthorTokenKind.atkRBrack:
+                case AuthorTokenKind.atkRBrack:// ] is not part of the tree
                     indentationInfo = node.GetNodeStartLineIndentation(this);
                     return indentationInfo;
-                case AuthorTokenKind.atkRCurly:
+                case AuthorTokenKind.atkRCurly:// } is not part of the tree
                     // if '}' is for a body-block, get indentation based on its parent.
                     if (node.AuthorNode.Details.Kind == AuthorParseNodeKind.apnkBlock && node.AuthorNode.EdgeLabel == AuthorParseNodeEdge.apneBody)
                         node = node.Parent;
                     indentationInfo = node.GetNodeStartLineIndentation(this);
                     return indentationInfo;
-                case AuthorTokenKind.atkWhile:
+                case AuthorTokenKind.atkWhile:// while (in do-while) is not part of the tree
                     if (node.AuthorNode.Details.Kind == AuthorParseNodeKind.apnkDoWhile) {
                         indentationInfo = node.GetNodeStartLineIndentation(this);
                         return indentationInfo;

tests/baselines/reference/switchStatementsWithMultipleDefaults.js

@@ -35,7 +35,7 @@ var x = 10;
 switch (x) {
     case 1:
     case 2:
-    default:
+    default:// No issues.
         break;
     default: // Error; second 'default' clause.
     default: // Error; third 'default' clause.
@@ -43,12 +43,12 @@ switch (x) {
         x *= x;
 }
 switch (x) {
-    default:
+    default:// No issues.
         break;
     case 100:
         switch (x * x) {
             default: // No issues.
-            default:
+            default:// Error; second 'default' clause.
                 break;
             case 10000:
                 x /= x;

tests/baselines/reference/switchStatementsWithMultipleDefaults1.js

@@ -17,7 +17,7 @@ var x = 10;
 switch (x) {
     case 1:
     case 2:
-    default:
+    default:// No issues.
         break;
     default: // Error; second 'default' clause.
     default: // Error; third 'default' clause.

tests/cases/compiler/commentsAfterCaseClauses1.ts

@@ -0,0 +1,14 @@
+function getSecurity(level) {
+    switch(level){
+        case 0: // Zero
+        case 1: // one
+        case 2: // two
+            return "Hi";
+        case 3: // three
+        case 4   : // four
+            return "hello";
+        case 5: // five
+        default:  // default
+            return "world";
+    }
+}

tests/cases/compiler/commentsAfterCaseClauses2.ts

@@ -0,0 +1,17 @@
+function getSecurity(level) {
+    switch(level){
+        case 0: // Zero
+        case 1: // one
+        case 2: // two
+            // Leading comments
+            return "Hi";
+        case 3: // three
+        case 4: // four
+            return "hello";
+        case 5: // five
+        default: // default
+            return "world";
+        // Comment After
+    } /*Comment 1*/ // Comment After 1
+    // Comment After 2
+}

tests/cases/compiler/commentsAfterCaseClauses3.ts

@@ -0,0 +1,16 @@
+function getSecurity(level) {
+    switch(level){
+        case 0: /*Zero*/
+        case 1: /*One*/ 
+        case 2: /*two*/
+            // Leading comments
+            return "Hi";
+        case 3: /*three*/
+        case 4: /*four*/
+            return "hello";
+        case 5: /*five*/
+        default:  /*six*/
+            return "world";
+    }
+    
+}