[dagster-dbt] Surface isolated dbt-fusion models in asset selection

[Vamsi-klu]

Summary

DbtProjectComponent (and any selection that goes through select_unique_ids) silently drops dbt models that contain no source()/ref() calls when the project is compiled with dbt-fusion (manifest schema v2+). The model is present and enabled in manifest["nodes"], yet it never appears as a Dagster asset and no error is raised.

Root cause

_select_unique_ids_from_manifest in dagster_dbt/utils.py builds the selection graph solely from manifest["child_map"]:

graph = graph_selector.Graph(DiGraph(incoming_graph_data=child_map))

dbt-core keys child_map by every node, but dbt-fusion omits any node that has neither parents nor children. A model with no source()/ref() calls (and nothing referencing it) is therefore absent from the DiGraph. NodeSelector intersects matched nodes with the graph's node set, so a node that is missing from the graph can never be selected — it is silently dropped.

Fix

After constructing the graph from child_map, add any selectable unique_ids from the manifest that are missing from the graph. This is a no-op for well-formed dbt-core manifests (where child_map already contains every node) and only repairs fusion manifests.

Testing

Added test_select_unique_ids_includes_isolated_fusion_models, which builds a manifest where an isolated model is absent from child_map (the exact dbt-fusion shape from the issue) and asserts the model is still selected. Verified the test fails without the fix and passes with it. ruff clean.

closes: #33801

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Was generative AI tooling used to author this PR?

Yes — Claude Code (Opus 4.8). Generated-by: Claude Code (Opus 4.8)

[greptile-apps]

Greptile Summary

This PR fixes a silent asset-drop in _select_unique_ids_from_manifest when a project is compiled with dbt-fusion: isolated models (no source()/ref() and no dependents) are absent from child_map in dbt-fusion manifests, so they were never added to the NetworkX DiGraph and were silently filtered out by NodeSelector.

• utils.py: After building the DiGraph from child_map, collect all selectable unique_ids from the eight known manifest collections and add any that are absent from the graph — a no-op for dbt-core manifests where child_map is already exhaustive.
• test_asset_selection.py: Two new test functions verify both point selection (isolated) and broad selection (fqn:*) on a minimal fusion-shaped manifest, and a second test validates a mixed graph that has a source-connected model alongside an isolated one.

Confidence Score: 5/5

Safe to merge — the change is additive and explicitly a no-op for well-formed dbt-core manifests.

The graph-backfill step only adds nodes; it never removes edges or rewrites existing graph data. For dbt-core manifests, child_map already contains every node, so the set difference is always empty and add_nodes_from is never called. For dbt-fusion manifests the fix restores the expected behavior. Tests confirm both the isolated-model regression and the mixed graph, and the production code path is narrow and well-understood.

No files require special attention.

Important Files Changed

Filename	Overview
python_modules/libraries/dagster-dbt/dagster_dbt/utils.py	Adds isolated-node backfill to the DiGraph before passing it to graph_selector.Graph; well-commented, no-op for dbt-core manifests, and covers all known selectable manifest collections.
python_modules/libraries/dagster-dbt/dagster_dbt_tests/core/test_asset_selection.py	Two new parameterized tests cover the core regression (isolated model absent from child_map) and a mixed graph with both connected and isolated nodes; helper builders keep the fixtures readable.

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    A[manifest_json] --> B[Build DiGraph from child_map]
    B --> C{Any selectable unique_ids\nmissing from graph?}
    C -- Yes\ndbt-fusion isolated nodes --> D[add_nodes_from missing ids]
    C -- No\nnormal dbt-core manifest --> E[No-op]
    D --> F[graph_selector.Graph]
    E --> F
    F --> G[NodeSelector]
    A --> H[Manifest object\nnodes / sources / metrics / etc.]
    H --> G
    G --> I[Apply select / exclude / selector string]
    I --> J[Return matched unique_ids]

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%%{init: {'theme': 'base', 'themeVariables': {"darkMode": true, "background": "#0d1117", "primaryColor": "#21262d", "primaryTextColor": "#e6edf3", "primaryBorderColor": "#8b949e", "lineColor": "#8b949e", "textColor": "#e6edf3", "edgeLabelBackground": "#161b22", "actorBkg": "#21262d", "actorBorder": "#8b949e", "actorTextColor": "#e6edf3", "actorLineColor": "#8b949e", "signalColor": "#8b949e", "signalTextColor": "#e6edf3", "noteBkgColor": "#373320", "noteBorderColor": "#d4a72c", "noteTextColor": "#f0e6c0", "labelBoxBkgColor": "#21262d", "labelBoxBorderColor": "#8b949e", "labelTextColor": "#e6edf3", "loopTextColor": "#e6edf3", "activationBkgColor": "#30363d", "activationBorderColor": "#8b949e"}}}%%
flowchart TD
    A[manifest_json] --> B[Build DiGraph from child_map]
    B --> C{Any selectable unique_ids\nmissing from graph?}
    C -- Yes\ndbt-fusion isolated nodes --> D[add_nodes_from missing ids]
    C -- No\nnormal dbt-core manifest --> E[No-op]
    D --> F[graph_selector.Graph]
    E --> F
    F --> G[NodeSelector]
    A --> H[Manifest object\nnodes / sources / metrics / etc.]
    H --> G
    G --> I[Apply select / exclude / selector string]
    I --> J[Return matched unique_ids]

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_{Reviews (2): Last reviewed commit: "[dagster-dbt] Expand dbt fusion isolated..." | Re-trigger Greptile}

[Vamsi-klu]

Just marked this ready for review. It's a small dagster-dbt change that surfaces isolated dbt-fusion models in asset selection, with a focused test added. @smackesey when you get a chance, could you take a look or route it to the right dbt owner? CI is gated for fork PRs, so it'll need a maintainer to unblock it. cc @cmpadden for triage. Thanks!