[typescript-angular] some models missing from api/*.service.ts imports -- 2.3.0

Description

additionalProperties models are not imported in generated typescript-angular api/*.service.ts files.

Swagger-codegen version

2.3.0

Swagger declaration file content or url

"responses": {
    "200": {
        "description": "OK",
        "schema": {
            "type": "object",
            "additionalProperties": {
                "type": "array",
                "items": {
                    "$ref": "#/definitions/MissingInServiceImports"
                }
            }
        }
    }
}

Entire swagger declaration file in this repo: https://github.com/jacksloan/broken-imports-typescript-codegen

Command line used for generation

java -jar modules/swagger-codegen-cli/target/swagger-codegen-cli.jar generate \
    -i swagger-spec.json \
    -l typescript-angular \
    --additional-properties npmRepository=https://nexus.xyz.com/repository/npm-internal \
    --additional-properties npmName=codegen-xyz \
    --additional-properties npmVersion=0.0.1 \
    --additional-properties ngVersion=4.3.0

Steps to reproduce

Run typescript-angular codegen against the spec file here: https://github.com/jacksloan/broken-imports-typescript-codegen

Snapshot used: https://oss.sonatype.org/content/repositories/snapshots/io/swagger/swagger-codegen-cli/2.3.0-SNAPSHOT/swagger-codegen-cli-2.3.0-20171216.033217-359.jar

Related issues/PRs

--

Suggest a fix/enhancement

I'll see what I can come up with. As a guess, could it be related to line 67-71 here?
https://github.com/swagger-api/swagger-codegen/blob/master/modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/TypeScriptAngularClientCodegen.java

Start with TypeScriptAngularClientCodegen.java around the referenced lines 67-71, then run the provided swagger-codegen command against the linked swagger-spec.json. Compare the generated typescript-angular api/*.service.ts files with the referenced definition and ensure models used through additionalProperties are imported.