format: move layers, scenarios and steps to bottom of scope.

ci/release/changelogs/next.md

@@ -7,6 +7,7 @@
 - Display version on CLI help invocation [#1400](https://github.com/terrastruct/d2/pull/1400)
 - Improved readability of connection labels when they overlap another connection. [#447](https://github.com/terrastruct/d2/pull/447)
 - Error message when `shape` is given a composite [#1415](https://github.com/terrastruct/d2/pull/1415)
+- The autoformatter moves board declarations to the bottom of its scope. [#1424](https://github.com/terrastruct/d2/pull/1424)
 
 #### Bugfixes ⛑️
 

d2ast/d2ast.go

@@ -794,6 +794,18 @@ func (mb MapNodeBox) Unbox() MapNode {
 	}
 }
 
+func (mb MapNodeBox) IsBoardNode() bool {
+	if mb.MapKey == nil || mb.MapKey.Key == nil || len(mb.MapKey.Key.Path) != 1 {
+		return false
+	}
+	switch mb.MapKey.Key.Path[0].Unbox().ScalarString() {
+	case "layers", "scenarios", "steps":
+		return true
+	default:
+		return false
+	}
+}
+
 // ArrayNodeBox is used to box ArrayNode for JSON persistence.
 type ArrayNodeBox struct {
 	Comment            *Comment            `json:"comment,omitempty"`

d2format/format.go

@@ -275,10 +275,27 @@ func (p *printer) _map(m *d2ast.Map) {
 		}
 	}
 
+	layerNodes := []d2ast.MapNodeBox{}
+	scenarioNodes := []d2ast.MapNodeBox{}
+	stepNodes := []d2ast.MapNodeBox{}
+
 	prev := d2ast.Node(m)
 	for i := 0; i < len(m.Nodes); i++ {
 		nb := m.Nodes[i]
 		n := nb.Unbox()
+		// extract out layer, scenario, and step nodes and skip
+		if nb.IsBoardNode() {
+			switch nb.MapKey.Key.Path[0].Unbox().ScalarString() {
+			case "layers":
+				layerNodes = append(layerNodes, nb)
+			case "scenarios":
+				scenarioNodes = append(scenarioNodes, nb)
+			case "steps":
+				stepNodes = append(stepNodes, nb)
+			}
+			prev = n
+			continue
+		}
 
 		// Handle inline comments.
 		if i > 0 && (nb.Comment != nil || nb.BlockComment != nil) {
@@ -306,6 +323,25 @@ func (p *printer) _map(m *d2ast.Map) {
 		prev = n
 	}
 
+	boards := []d2ast.MapNodeBox{}
+	boards = append(boards, layerNodes...)
+	boards = append(boards, scenarioNodes...)
+	boards = append(boards, stepNodes...)
+
+	// draw board nodes
+	for i := 0; i < len(boards); i++ {
+		n := boards[i].Unbox()
+		// if this board is the very first line of the file, don't add an extra indent
+		if n.GetRange().Start.Line != 0 {
+			p.newline()
+		}
+		if len(m.Nodes) > len(boards) {
+			p.newline()
+		}
+		p.node(n)
+		prev = n
+	}
+
 	if !m.IsFileMap() {
 		if !m.Range.OneLine() {
 			p.deindent()

d2format/format_test.go

@@ -152,14 +152,14 @@ meow
     representation: {type: jsonb}
     diagram: int {constraint: foreign_key}
   }
-
+  meow <- diagrams.id
+
   steps: {
     shape: sql_table
     id: {type: int; constraint: primary_key}
     representation: {type: jsonb}
     diagram: int {constraint: foreign_key}
   }
-  meow <- diagrams.id
 }
 
 D2 AST Parser: {
@@ -657,6 +657,145 @@ x: @../file
 x: @"x/../file"
 `,
 			exp: `x: @file
+`,
+		},
+		{
+			name: "layers_scenarios_steps_bottom_simple",
+			in: `layers: {
+  b: {
+		e
+    scenarios: {
+      p: { 
+        x 
+      }
+    }
+  }
+}
+`,
+			exp: `layers: {
+  b: {
+    e
+
+    scenarios: {
+      p: {
+        x
+      }
+    }
+  }
+}
+`,
+		},
+		{
+			name: "layers_scenarios_steps_bottom_complex",
+			in: `a
+
+scenarios: {
+
+
+
+	scenario-1: {
+		steps: {
+			step-1: {
+        Test
+			}
+			step-2
+		}
+		non-step
+	}
+}
+
+layers: {
+  Test super nested: {
+		base-layer
+		layers: {
+			layers: {
+				grand-child-layer: {
+					grand-child-board
+				}
+			}
+			layer-board
+		}
+		last-layer
+	}
+}
+b
+steps: {
+	1: {
+		step-1-content
+	}
+}
+
+
+scenarios: {
+	scenario-2: {
+		scenario-2-content
+	}
+}
+
+c
+d
+
+only-layers: {
+	layers: {
+		X
+		Y
+	}
+}
+`,
+			exp: `a
+b
+
+c
+d
+
+only-layers: {
+  layers: {
+    X
+    Y
+  }
+}
+
+layers: {
+  Test super nested: {
+    base-layer
+    last-layer
+
+    layers: {
+      layer-board
+
+      layers: {
+        grand-child-layer: {
+          grand-child-board
+        }
+      }
+    }
+  }
+}
+
+scenarios: {
+  scenario-1: {
+    non-step
+
+    steps: {
+      step-1: {
+        Test
+      }
+      step-2
+    }
+  }
+}
+
+scenarios: {
+  scenario-2: {
+    scenario-2-content
+  }
+}
+
+steps: {
+  1: {
+    step-1-content
+  }
+}
 `,
 		},
 	}