From 0cd3a662ced371ca01cd21e89d8225501cc415f9 Mon Sep 17 00:00:00 2001
From: itchyny <itchyny@cybozu.co.jp>
Date: Thu, 18 Apr 2024 13:05:43 +0900
Subject: [PATCH] improve compiler to abort with error if query is missing

---
 cli/test.yaml | 37 +++++++++++++++++++++++++++++--------
 compiler.go   |  2 ++
 parser.go     |  2 +-
 parser.go.y   |  2 +-
 4 files changed, 33 insertions(+), 10 deletions(-)

diff --git a/cli/test.yaml b/cli/test.yaml
index fedecde8..c8d0a770 100644
--- a/cli/test.yaml
+++ b/cli/test.yaml
@@ -1,22 +1,36 @@
 - name: empty input
+  args:
+    - '.'
   input: ''
   expected: ''
 
-- name: empty query
+- name: empty args
+  input: 'null'
+  expected: |
+    null
+
+- name: missing query
   args:
     - ''
-  input: '128'
+  error: |
+    compile error: missing query (try ".")
+  exit_code: 3
+
+- name: query with comment
+  args:
+    - '. # comment'
+  input: 'null'
   expected: |
-    128
+    null
 
-- name: comment only query
+- name: missing query with comment
   args:
     - '# comment'
-  input: '128'
-  expected: |
-    128
+  error: |
+    compile error: missing query (try ".")
+  exit_code: 3
 
-- name: query with comment
+- name: query with comment with newline
   args:
     - |
       # comment
@@ -2574,6 +2588,13 @@
             ^  unexpected token "$f"
   exit_code: 3
 
+- name: function declaration without query
+  args:
+    - 'def f: 0;'
+  error: |
+    compile error: missing query (try ".")
+  exit_code: 3
+
 - name: add, subtract, multiply, divide, modulo numbers
   args:
     - -c
diff --git a/compiler.go b/compiler.go
index d114f27b..b2788c05 100644
--- a/compiler.go
+++ b/compiler.go
@@ -398,6 +398,8 @@ func (c *compiler) compileQuery(e *Query) error {
 		return c.compileTerm(e.Term)
 	}
 	switch e.Op {
+	case Operator(0):
+		return errors.New(`missing query (try ".")`)
 	case OpPipe:
 		if err := c.compileQuery(e.Left); err != nil {
 			return err
diff --git a/parser.go b/parser.go
index 61501f87..561ed396 100644
--- a/parser.go
+++ b/parser.go
@@ -837,7 +837,7 @@ yydefault:
 		yyDollar = yyS[yypt-1 : yypt+1]
 //line parser.go.y:104
 		{
-			yyVAL.value = &Query{FuncDefs: reverseFuncDef(yyDollar[1].value.([]*FuncDef)), Term: &Term{Type: TermTypeIdentity}}
+			yyVAL.value = &Query{FuncDefs: reverseFuncDef(yyDollar[1].value.([]*FuncDef))}
 		}
 	case 12:
 		yyDollar = yyS[yypt-0 : yypt+1]
diff --git a/parser.go.y b/parser.go.y
index 7354c645..29bed07c 100644
--- a/parser.go.y
+++ b/parser.go.y
@@ -102,7 +102,7 @@ meta
 body
     : funcdefs
     {
-        $$ = &Query{FuncDefs: reverseFuncDef($1.([]*FuncDef)), Term: &Term{Type: TermTypeIdentity}}
+        $$ = &Query{FuncDefs: reverseFuncDef($1.([]*FuncDef))}
     }
     | query