Exception: No Flutter represented type found for type null.

[Kahoulam]

Steps to reproduce

1. Create a new project
2. Add tokens.json file
3. Execute the command dart run build_runner build

Expected results

Correctly generate tokens.dart file

Actual results

An error occurred:

Exception: No Flutter represented type found for type null.

Version

design_tokens_builder: ^0.2.0+1

Code sample

tokens.json

{
  "global": {
    "M3": {
      "ref": {
        "primary": {
          "primary0": {
            "value": "#000000",
            "type": "color"
          },
          "primary10": {
            "value": "#1d1d00",
            "type": "color"
          },
          "primary20": {
            "value": "#323200",
            "type": "color"
          },
          "primary30": {
            "value": "#494900",
            "type": "color"
          },
          "primary40": {
            "value": "#626200",
            "type": "color"
          },
          "primary50": {
            "value": "#7b7b00",
            "type": "color"
          },
          "primary60": {
            "value": "#969600",
            "type": "color"
          },
          "primary70": {
            "value": "#b1b100",
            "type": "color"
          },
          "primary80": {
            "value": "#cdcd00",
            "type": "color"
          },
          "primary90": {
            "value": "#eaea00",
            "type": "color"
          },
          "primary95": {
            "value": "#f9f900",
            "type": "color"
          },
          "primary99": {
            "value": "#fffbff",
            "type": "color"
          },
          "primary100": {
            "value": "#ffffff",
            "type": "color"
          },
          "primary4": {
            "value": "#0f0f00",
            "type": "color"
          },
          "primary5": {
            "value": "#121200",
            "type": "color"
          },
          "primary6": {
            "value": "#141400",
            "type": "color"
          },
          "primary12": {
            "value": "#212100",
            "type": "color"
          },
          "primary17": {
            "value": "#2c2c00",
            "type": "color"
          },
          "primary22": {
            "value": "#373700",
            "type": "color"
          },
          "primary24": {
            "value": "#3b3b00",
            "type": "color"
          },
          "primary25": {
            "value": "#3e3e00",
            "type": "color"
          },
          "primary35": {
            "value": "#555500",
            "type": "color"
          },
          "primary87": {
            "value": "#e1e100",
            "type": "color"
          },
          "primary92": {
            "value": "#f0f000",
            "type": "color"
          },
          "primary94": {
            "value": "#f6f600",
            "type": "color"
          },
          "primary96": {
            "value": "#fcfc00",
            "type": "color"
          },
          "primary98": {
            "value": "#fffeac",
            "type": "color"
          }
        },
        "secondary": {
          "secondary0": {
            "value": "#000000",
            "type": "color"
          },
          "secondary10": {
            "value": "#1d1d06",
            "type": "color"
          },
          "secondary20": {
            "value": "#323218",
            "type": "color"
          },
          "secondary30": {
            "value": "#49482d",
            "type": "color"
          },
          "secondary40": {
            "value": "#606043",
            "type": "color"
          },
          "secondary50": {
            "value": "#7a795a",
            "type": "color"
          },
          "secondary60": {
            "value": "#949272",
            "type": "color"
          },
          "secondary70": {
            "value": "#aead8b",
            "type": "color"
          },
          "secondary80": {
            "value": "#cac8a5",
            "type": "color"
          },
          "secondary90": {
            "value": "#e7e4bf",
            "type": "color"
          },
          "secondary95": {
            "value": "#f5f3cd",
            "type": "color"
          },
          "secondary99": {
            "value": "#fffbff",
            "type": "color"
          },
          "secondary100": {
            "value": "#ffffff",
            "type": "color"
          },
          "secondary4": {
            "value": "#0f0f00",
            "type": "color"
          },
          "secondary5": {
            "value": "#121201",
            "type": "color"
          },
          "secondary6": {
            "value": "#141402",
            "type": "color"
          },
          "secondary12": {
            "value": "#212109",
            "type": "color"
          },
          "secondary17": {
            "value": "#2b2b12",
            "type": "color"
          },
          "secondary22": {
            "value": "#36361c",
            "type": "color"
          },
          "secondary24": {
            "value": "#3b3a20",
            "type": "color"
          },
          "secondary25": {
            "value": "#3d3d22",
            "type": "color"
          },
          "secondary35": {
            "value": "#545438",
            "type": "color"
          },
          "secondary87": {
            "value": "#dedcb7",
            "type": "color"
          },
          "secondary92": {
            "value": "#eceac5",
            "type": "color"
          },
          "secondary94": {
            "value": "#f2f0ca",
            "type": "color"
          },
          "secondary96": {
            "value": "#f8f5cf",
            "type": "color"
          },
          "secondary98": {
            "value": "#fefbd5",
            "type": "color"
          }
        },
        "tertiary": {
          "tertiary0": {
            "value": "#000000",
            "type": "color"
          },
          "tertiary10": {
            "value": "#002117",
            "type": "color"
          },
          "tertiary20": {
            "value": "#0b372a",
            "type": "color"
          },
          "tertiary30": {
            "value": "#254e40",
            "type": "color"
          },
          "tertiary40": {
            "value": "#3d6657",
            "type": "color"
          },
          "tertiary50": {
            "value": "#567f6f",
            "type": "color"
          },
          "tertiary60": {
            "value": "#6f9a88",
            "type": "color"
          },
          "tertiary70": {
            "value": "#89b4a2",
            "type": "color"
          },
          "tertiary80": {
            "value": "#a4d0bd",
            "type": "color"
          },
          "tertiary90": {
            "value": "#bfecd8",
            "type": "color"
          },
          "tertiary95": {
            "value": "#cdfbe6",
            "type": "color"
          },
          "tertiary99": {
            "value": "#f4fff8",
            "type": "color"
          },
          "tertiary100": {
            "value": "#ffffff",
            "type": "color"
          },
          "tertiary4": {
            "value": "#00120b",
            "type": "color"
          },
          "tertiary5": {
            "value": "#00150d",
            "type": "color"
          },
          "tertiary6": {
            "value": "#00170f",
            "type": "color"
          },
          "tertiary12": {
            "value": "#00251a",
            "type": "color"
          },
          "tertiary17": {
            "value": "#033124",
            "type": "color"
          },
          "tertiary22": {
            "value": "#113c2e",
            "type": "color"
          },
          "tertiary24": {
            "value": "#164032",
            "type": "color"
          },
          "tertiary25": {
            "value": "#194334",
            "type": "color"
          },
          "tertiary35": {
            "value": "#315a4b",
            "type": "color"
          },
          "tertiary87": {
            "value": "#b7e4d0",
            "type": "color"
          },
          "tertiary92": {
            "value": "#c5f2de",
            "type": "color"
          },
          "tertiary94": {
            "value": "#cbf8e3",
            "type": "color"
          },
          "tertiary96": {
            "value": "#d0fee9",
            "type": "color"
          },
          "tertiary98": {
            "value": "#e7fff2",
            "type": "color"
          }
        }
      }
    }
  },
  "$themes": [],
  "$metadata": {
    "tokenSetOrder": [
      "global"
    ]
  }
}

Logs

Console logs

[INFO] Generating build script completed, took 244ms
[INFO] Reading cached asset graph completed, took 66ms
[INFO] Checking for updates since last build completed, took 887ms
[WARNING] design_tokens_builder|lib/design_tokens_builder.dart was not found in the asset graph, incremental builds will not work.
 This probably means you don't have your dependencies specified fully in your pubspec.yaml.
[WARNING] Invalidating asset graph due to build script update!
[INFO] Cleaning up outputs from previous builds. completed, took 1ms
[INFO] Generating build script completed, took 40ms
[WARNING] Invalidated precompiled build script due to missing asset graph.
[INFO] Precompiling build script... completed, took 618ms
[WARNING] design_tokens_builder|lib/design_tokens_builder.dart was not found in the asset graph, incremental builds will not work.
 This probably means you don't have your dependencies specified fully in your pubspec.yaml.
[INFO] Building new asset graph completed, took 908ms
[INFO] Checking for unexpected pre-existing outputs. completed, took 0ms
[SEVERE] design_tokens_builder on lib/$lib$:

Exception: No Flutter represented type found for type null.
[INFO] Running build completed, took 47ms
[INFO] Caching finalized dependency graph completed, took 43ms
[SEVERE] Failed after 97ms

Flutter Doctor output

Doctor output

[✓] Flutter (Channel stable, 3.16.0, on macOS 14.0 23A344 darwin-arm64, locale en-TW)
[✓] Android toolchain - develop for Android devices (Android SDK version 33.0.1)
[✓] Xcode - develop for iOS and macOS (Xcode 15.0.1)
[✓] Chrome - develop for the web
[✓] Android Studio (version 2022.3)
[✓] VS Code (version 1.84.2)
[✓] Connected device (1 available)
[✓] Network resources