Fix parser to continue parsing key-value pairs after an If-Statement value in a HashExpression (#7002)

daxian-dbw · web-flow · commit b20dd31398e0 · 2018-06-06T09:38:05.000-07:00
After parsing `if () { }`, new lines are skipped in order to see if either `elseif` or `else` is present. When neither is present, we should resync back to the pointer before skipping those possibly available new lines, so that the new line tokens can be utilized by the subsequent parsing.
diff --git a/src/System.Management.Automation/engine/parser/Parser.cs b/src/System.Management.Automation/engine/parser/Parser.cs
@@ -2411,6 +2411,16 @@ private StatementAst IfStatementRule(Token ifToken)
 
                 clauses.Add(new IfClause(condition, body));
 
+                // Save a restore point here. In case there is no 'elseif' or 'else' following,
+                // we should resync back here to preserve the possible new lines. The new lines
+                // could be important for the following parsing. For example, in case we are in
+                // a HashExpression, a new line might be needed for parsing the key-value that
+                // is following the if statement:
+                //    @{
+                //       a = if (1) {}
+                //       b = 10
+                //    }
+                int restorePoint = _ungotToken == null ? _tokenizer.GetRestorePoint() : _ungotToken.Extent.StartOffset;
                 SkipNewlines();
                 keyword = PeekToken();
 
@@ -2419,8 +2429,7 @@ private StatementAst IfStatementRule(Token ifToken)
                     SkipToken();
                     continue;
                 }
-
-                if (keyword.Kind == TokenKind.Else)
+                else if (keyword.Kind == TokenKind.Else)
                 {
                     SkipToken();
                     SkipNewlines();
@@ -2436,6 +2445,11 @@ private StatementAst IfStatementRule(Token ifToken)
                         return new ErrorStatementAst(ExtentOf(ifToken, keyword), componentAsts);
                     }
                 }
+                else
+                {
+                    // There is no 'elseif' or 'else' following, so resync back to the possible new lines.
+                    Resync(restorePoint);
+                }
                 break;
             }
 
diff --git a/test/powershell/Language/Parser/LanguageAndParser.TestFollowup.Tests.ps1 b/test/powershell/Language/Parser/LanguageAndParser.TestFollowup.Tests.ps1
@@ -212,3 +212,94 @@ Describe "Members of System.Type" -Tags "CI" {
         [MyType].ImplementedInterfaces | Should -Be System.Collections.IEnumerable
     }
 }
+
+Describe "Hash expression with if statement as value" -Tags "CI" {
+    BeforeAll {
+        # With no extra new lines after if-statement
+        $hash1 = @{
+            a = if (1) {'a'}
+            b = 'b'
+            c = if (0) {2} elseif (1) {'c'}
+            d = 'd'
+            e = if (0) {2} elseif (0) {2} else {'e'}
+            f = 'f'
+            g = if (0) {2} else {'g'}
+            h = 'h'
+        }
+
+        # With extra new lines after if-statement
+        $hash2 = @{
+            a = if (1) {'a'}
+
+            b = 'b'
+            c = if (0) {2} elseif (1) {'c'}
+
+            d = 'd'
+            e = if (0) {2} elseif (0) {2} else {'e'}
+
+            f = 'f'
+            g = if (0) {2} else {'g'}
+
+            h = 'h'
+        }
+
+        # With expanded if-statement
+        $hash3 = @{
+            a = if (1)
+                {
+                    'a'
+                }
+            b = 'b'
+            c = if (0)
+                {
+                    2
+                }
+                elseif (1)
+                {
+                    'c'
+                }
+            d = 'd'
+            e = if (0)
+                {
+                    2
+                }
+                elseif (0)
+                {
+                    2
+                }
+                else
+                {
+                    'e'
+                }
+            f = 'f'
+            g = if (0)
+                {
+                    2
+                }
+                else
+                {
+                    'g'
+                }
+            h = 'h'
+        }
+
+        $testCases = @(
+            @{ name = "No extra new lines"; hash = $hash1 }
+            @{ name = "With extra new lines"; hash = $hash2 }
+            @{ name = "With expanded if-statement"; hash = $hash3 }
+        )
+    }
+
+    It "Key-value pairs after an if-statement-value in a HashExpression should continue to be parsed - <name>" -TestCases $testCases {
+        param($hash)
+
+        $hash['a'] | Should -BeExactly 'a'
+        $hash['b'] | Should -BeExactly 'b'
+        $hash['c'] | Should -BeExactly 'c'
+        $hash['d'] | Should -BeExactly 'd'
+        $hash['e'] | Should -BeExactly 'e'
+        $hash['f'] | Should -BeExactly 'f'
+        $hash['g'] | Should -BeExactly 'g'
+        $hash['h'] | Should -BeExactly 'h'
+    }
+}
