Merge pull request #1364 from berniexie/no-empty-block-strings

compile: no empty block strings

ci/release/changelogs/next.md

@@ -18,3 +18,4 @@
 - Fixes panic using reserved keywords as containers [#1358](https://github.com/terrastruct/d2/pull/1358)
 - When multiple classes are applied changing different attributes of arrowheads, they are
   all applied instead of only the last one [#1362](https://github.com/terrastruct/d2/pull/1362)
+- Prevent empty block strings [#1364](https://github.com/terrastruct/d2/pull/1364)

d2compiler/compile.go

@@ -270,6 +270,9 @@ func (c *compiler) compileLabel(attrs *d2graph.Attributes, f d2ir.Node) {
 		// TODO: Delete instead.
 		attrs.Label.Value = scalar.ScalarString()
 	case *d2ast.BlockString:
+		if strings.TrimSpace(scalar.ScalarString()) == "" {
+			c.errorf(f.LastPrimaryKey(), "block string cannot be empty")
+		}
 		attrs.Language = scalar.Tag
 		fullTag, ok := ShortToFullLanguageAliases[scalar.Tag]
 		if ok {

d2compiler/compile_test.go

@@ -610,6 +610,24 @@ x: {
 			expErr: `d2/testdata/d2compiler/TestCompile/md_block_string_err.d2:4:19: unexpected text after md block string. See https://d2lang.com/tour/text#advanced-block-strings.
 d2/testdata/d2compiler/TestCompile/md_block_string_err.d2:5:1: block string must be terminated with |`,
 		},
+		{
+			name:   "no_empty_block_string",
+			text:   `Text: |md |`,
+			expErr: `d2/testdata/d2compiler/TestCompile/no_empty_block_string.d2:1:1: block string cannot be empty`,
+		},
+		{
+			name:   "no_white_spaces_only_block_string",
+			text:   `Text: |md      |`,
+			expErr: `d2/testdata/d2compiler/TestCompile/no_white_spaces_only_block_string.d2:1:1: block string cannot be empty`,
+		},
+		{
+			name: "no_new_lines_only_block_string",
+			text: `Text: |md
+
+
+|`,
+			expErr: `d2/testdata/d2compiler/TestCompile/no_new_lines_only_block_string.d2:1:1: block string cannot be empty`,
+		},
 		{
 			name: "underscore_edge_existing",
 

e2etests/measured_test.go

@@ -26,14 +26,6 @@ func testMeasured(t *testing.T) {
 			name:   "empty-sql_table",
 			mtexts: []*d2target.MText{},
 			script: `a: "" { shape: sql_table }
-`,
-		},
-		{
-			name:   "empty-markdown",
-			mtexts: []*d2target.MText{},
-			script: `a: |md
-` + " " + `
-|
 `,
 		},
 	}

e2etests/regression_test.go

@@ -929,19 +929,6 @@ cf many required: {
 		style.stroke-width: 8
 	}
 }
-`,
-		},
-		{
-			name: "empty_md_measurement",
-			script: `
-a
-b: |md
-
-
-|
-c
-d
-a -> b -> c
 `,
 		},
 		loadFromFile(t, "slow_grid"),

testdata/d2compiler/TestCompile/no_empty_block_string.exp.json

@@ -0,0 +1,12 @@
+{
+  "graph": null,
+  "err": {
+    "ioerr": null,
+    "errs": [
+      {
+        "range": "d2/testdata/d2compiler/TestCompile/no_empty_block_string.d2,0:0:0-0:11:11",
+        "errmsg": "d2/testdata/d2compiler/TestCompile/no_empty_block_string.d2:1:1: block string cannot be empty"
+      }
+    ]
+  }
+}

testdata/d2compiler/TestCompile/no_empty_block_strings.exp.json

@@ -0,0 +1,12 @@
+{
+  "graph": null,
+  "err": {
+    "ioerr": null,
+    "errs": [
+      {
+        "range": "d2/testdata/d2compiler/TestCompile/no_empty_block_strings.d2,0:0:0-0:11:11",
+        "errmsg": "d2/testdata/d2compiler/TestCompile/no_empty_block_strings.d2:1:1: block string cannot be empty"
+      }
+    ]
+  }
+}

testdata/d2compiler/TestCompile/no_new_lines_only_block_string.exp.json

@@ -0,0 +1,12 @@
+{
+  "graph": null,
+  "err": {
+    "ioerr": null,
+    "errs": [
+      {
+        "range": "d2/testdata/d2compiler/TestCompile/no_new_lines_only_block_string.d2,0:0:0-3:1:13",
+        "errmsg": "d2/testdata/d2compiler/TestCompile/no_new_lines_only_block_string.d2:1:1: block string cannot be empty"
+      }
+    ]
+  }
+}

testdata/d2compiler/TestCompile/no_white_spaces_only_block_string.exp.json

@@ -0,0 +1,12 @@
+{
+  "graph": null,
+  "err": {
+    "ioerr": null,
+    "errs": [
+      {
+        "range": "d2/testdata/d2compiler/TestCompile/no_white_spaces_only_block_string.d2,0:0:0-0:16:16",
+        "errmsg": "d2/testdata/d2compiler/TestCompile/no_white_spaces_only_block_string.d2:1:1: block string cannot be empty"
+      }
+    ]
+  }
+}