Fix expression grammar to work with boolean functions

Author: SteveL-MSFT

dsc/tests/dsc_functions.tests.ps1

@@ -120,7 +120,7 @@ Describe 'tests for function expressions' {
     @{ expression = "[intersection(parameters('firstObject'), parameters('firstArray'))]"; isError = $true }
     @{ expression = "[intersection(parameters('firstArray'), parameters('secondArray'), parameters('fifthArray'))]"; expected = @('cd') }
     @{ expression = "[intersection(parameters('firstObject'), parameters('secondObject'), parameters('sixthObject'))]"; expected = [pscustomobject]@{ two = 'b' } }
-    @{ expression = "[intersection(parameters('nestedObject1'), parameters('nestedObject2'))]"; expected = [pscustomobject]@{ 
+    @{ expression = "[intersection(parameters('nestedObject1'), parameters('nestedObject2'))]"; expected = [pscustomobject]@{
       shared = [pscustomobject]@{ value = 42; flag = $true }
       level = 1
     } }
@@ -711,9 +711,30 @@ Describe 'tests for function expressions' {
               properties:
                 output: `"$expression`"
 "@
-    $out = dsc -l trace config get -i $config_yaml 2>$TestDrive/error.log
+    $null = dsc -l trace config get -i $config_yaml 2>$TestDrive/error.log
     $LASTEXITCODE | Should -Not -Be 0
     $errorContent = Get-Content $TestDrive/error.log -Raw
     $errorContent | Should -Match ([regex]::Escape($expectedError))
   }
+
+  It 'mixed booleans with functions works' -TestCases @(
+    @{ expression = "[and(true(), false, not(false))]"; expected = $false }
+    @{ expression = "[or(false, false(), not(false()))]"; expected = $true }
+    @{ expression = "[and(true(), true, not(false))]"; expected = $true }
+    @{ expression = "[or(false, false(), not(true()))]"; expected = $false }
+  ) {
+    param($expression, $expected)
+
+    $config_yaml = @"
+            `$schema: https://aka.ms/dsc/schemas/v3/bundled/config/document.json
+            resources:
+            - name: Echo
+              type: Microsoft.DSC.Debug/Echo
+              properties:
+                output: "$expression"
+"@
+    $out = dsc -l trace config get -i $config_yaml 2>$TestDrive/error.log | ConvertFrom-Json
+    $LASTEXITCODE | Should -Be 0 -Because (Get-Content $TestDrive/error.log -Raw)
+    $out.results[0].result.actualState.output | Should -BeExactly $expected
+  }
 }

tree-sitter-dscexpression/grammar.js

@@ -1,6 +1,8 @@
 const PREC = {
   ESCAPEDSTRING: 2,
   EXPRESSIONSTRING: 1,
+  FUNCTION: 1,
+  BOOLEAN: 0,
   STRINGLITERAL: -11,
 }
 
@@ -20,16 +22,20 @@ module.exports = grammar({
     expression: $ => seq(field('function', $.function), optional(field('accessor',$.accessor))),
     stringLiteral: $ => token(prec(PREC.STRINGLITERAL, /[^\[](.|\n)*?/)),
 
-    function: $ => seq(field('name', $.functionName), '(', field('args', optional($.arguments)), ')'),
-    functionName: $ => /[a-zA-Z][a-zA-Z0-9]*(\.[a-zA-Z0-9]+)?/,
+    function: $ => prec(PREC.FUNCTION, seq(field('name', $.functionName), '(', field('args', optional($.arguments)), ')')),
+    functionName: $ => choice(
+      /[a-zA-Z][a-zA-Z0-9]*(\.[a-zA-Z0-9]+)?/,
+      $._booleanLiteral
+    ),
     arguments: $ => seq($._argument, repeat(seq(',', $._argument))),
     _argument: $ => choice($.expression, $._quotedString, $.number, $.boolean),
 
     _quotedString: $ => seq('\'', $.string, '\''),
     // ARM strings are not allowed to contain single-quote characters unless escaped
     string: $ => /([^']|''|\n)*/,
     number: $ => /-?\d+/,
-    boolean: $ => choice('true', 'false'),
+    boolean: $ => prec(PREC.BOOLEAN, $._booleanLiteral),
+    _booleanLiteral: $ => choice('true', 'false'),
 
     accessor: $ => repeat1(choice($.memberAccess, $.index)),
 

tree-sitter-dscexpression/test/corpus/invalid_expressions.txt

@@ -18,7 +18,6 @@ String parameter not in quotes
         (function
           (functionName)
           (ERROR
-            (functionName)
             (functionName)))))
 
 =====
@@ -79,8 +78,6 @@ String starting with bracket
 ---
 
     (ERROR
-      (ERROR
-        (functionName))
       (functionName))
 
 =====
@@ -179,8 +176,7 @@ Expression with member accessor outside
           (functionName)
           (arguments
             (number))))
-      (ERROR
-        (functionName)))
+      (ERROR))
 
 =====
 Expression with index accessor outside
@@ -209,6 +205,4 @@ String with un-escaped single-quote
           (functionName)
           (arguments
             (string))
-          (ERROR
-            (functionName)
-            (functionName)))))
+          (ERROR))))

tree-sitter-dscexpression/test/corpus/valid_expressions.txt

@@ -34,7 +34,7 @@ Simple expression
 =====
 Multiple arguments
 =====
-[myFunction('argString', 1, -1, true)]
+[myFunction('argString', 1, -1, true, false)]
 ---
 
 (statement
@@ -45,6 +45,7 @@ Multiple arguments
         (string)
         (number)
         (number)
+        (boolean)
         (boolean)))))
 
 =====
@@ -335,3 +336,19 @@ User Function
       (arguments
         (number)
         (number)))))
+
+=====
+User Function with nested function
+=====
+[Environment.getEnvironmentConfig(true(), false)]
+---
+
+(statement
+      (expression
+        (function
+          (functionName)
+          (arguments
+            (expression
+              (function
+                (functionName)))
+            (boolean)))))