fix: 'explain' omitted the instruction line in some Boolean expressions

docs/Queries/Explaining Queries.md

@@ -114,7 +114,8 @@ Explanation of this Tasks code block query:
 
   (due before tomorrow) AND (is recurring) =>
     AND (All of):
-      due date is before 2022-10-22 (Saturday 22nd October 2022)
+      due before tomorrow =>
+        due date is before 2022-10-22 (Saturday 22nd October 2022)
       is recurring
 
   No grouping instructions supplied.

src/Query/Filter/BooleanField.ts

@@ -200,7 +200,15 @@ export class BooleanField extends Field {
             throw Error('null token value'); // This should not happen
         }
         const filter = this.subFields[token.value.trim()];
-        explanationStack.push(filter.explanation);
+        const explanation = this.simulateExplainFilter(filter);
+        explanationStack.push(explanation);
+    }
+
+    private simulateExplainFilter(filter: Filter) {
+        // In our caller, the explanationStack keeps the explanations but not the instruction lines.
+        // So to replicate the logic in Filter.explainFilterIndented(), we may need to add the
+        // instruction to the explanation.
+        return filter.simulateExplainFilter();
     }
 
     private explainOperator(token: Token, explanationStack: Explanation[]) {

src/Query/Filter/Filter.ts

@@ -1,5 +1,5 @@
 import type { Task } from '../../Task/Task';
-import type { Explanation } from '../Explain/Explanation';
+import { Explanation } from '../Explain/Explanation';
 import type { SearchInfo } from '../SearchInfo';
 import { Statement } from '../Statement';
 
@@ -64,4 +64,13 @@ export class Filter {
             return `${explainedStatement} =>\n${explanation.asString(indent + '  ')}\n`;
         }
     }
+
+    public simulateExplainFilter() {
+        const needToShowInstruction = this.instruction !== this.explanation.asString();
+        if (needToShowInstruction) {
+            return new Explanation(this.instruction + ' =>', [this.explanation]);
+        } else {
+            return this.explanation;
+        }
+    }
 }

tests/Query/Explain/DocsSamplesForExplain.test.explain_boolean_combinations.approved.explanation.text

@@ -4,7 +4,8 @@ Explanation of this Tasks code block query:
 
   (due before tomorrow) AND (is recurring) =>
     AND (All of):
-      due date is before 2022-10-22 (Saturday 22nd October 2022)
+      due before tomorrow =>
+        due date is before 2022-10-22 (Saturday 22nd October 2022)
       is recurring
 
   No grouping instructions supplied.

tests/Query/Filter/BooleanField.test.boolean_query_-_exhaustive_tests_explain.approved.txt

@@ -219,7 +219,8 @@ Result:
   (description includes d1) AND (priority medium) =>
     AND (All of):
       description includes d1
-      priority is medium
+      priority medium =>
+        priority is medium
 
 
 --------------------------------------------------------
@@ -247,7 +248,8 @@ Result:
     AND (All of):
       description includes d1
       NOT:
-        priority is medium
+        priority medium =>
+          priority is medium
 
 
 --------------------------------------------------------
@@ -274,7 +276,8 @@ Result:
     OR (At least one of):
       description includes d1
       description includes d2
-      priority is medium
+      priority medium =>
+        priority is medium
 
 
 --------------------------------------------------------
@@ -287,7 +290,8 @@ Result:
   (description includes d1) OR (priority medium) =>
     OR (At least one of):
       description includes d1
-      priority is medium
+      priority medium =>
+        priority is medium
 
 
 --------------------------------------------------------
@@ -315,7 +319,8 @@ Result:
     OR (At least one of):
       description includes d1
       NOT:
-        priority is medium
+        priority medium =>
+          priority is medium
 
 
 --------------------------------------------------------
@@ -341,7 +346,8 @@ Result:
   (description includes d1) XOR (priority medium) =>
     XOR (Exactly one of):
       description includes d1
-      priority is medium
+      priority medium =>
+        priority is medium
 
 
 --------------------------------------------------------

tests/Query/Filter/BooleanField.test.ts

@@ -220,7 +220,7 @@ describe('boolean query - explain', () => {
         return new Explainer(indentation).explainFilters(query1);
     }
 
-    it.failing('should make multi-line explanations consistent in and out of Boolean filter - issue #2707', () => {
+    it('should make multi-line explanations consistent in and out of Boolean filter - issue #2707', () => {
         // See https://github.com/obsidian-tasks-group/obsidian-tasks/issues/2707
         const filter = 'description regex matches /buy/i';
 
@@ -231,7 +231,6 @@ describe('boolean query - explain', () => {
         const filter2Explanation = explainFilters(0, filter2);
 
         // Ensure that the full standalone explanation of filter1 is present in its explanation in the Boolean query:
-        // TODO: Make this test pass:
         expect(filter2Explanation).toContain(filter1Explanation);
 
         // These inline snapshots are provided for ease of visualising the behaviour:
@@ -241,12 +240,12 @@ describe('boolean query - explain', () => {
             "
         `);
 
-        // TODO: Include the original regex source line in this string:
         expect(filter2Explanation).toMatchInlineSnapshot(`
             "( description regex matches /buy/i ) AND ( path includes {{query.file.path}} ) =>
             ( description regex matches /buy/i ) AND ( path includes some/sample/note.md ) =>
               AND (All of):
-                using regex:            'buy' with flag 'i'
+                description regex matches /buy/i =>
+                  using regex:            'buy' with flag 'i'
                 path includes some/sample/note.md
             "
         `);