Docker Compose. Call a custom script

I have a simple docker-compose definition where I want to run a simple cmd/bash command:

basictests:
  image: ${DOCKER_REGISTRY-}mytests
  build:
    context: .
    dockerfile: MyTests/Dockerfile
  container_name: "mytestscontainer"
  command: 
    - echo "test"
  depends_on:
    dependent_env:
      condition: service_healthy 

note: It's a simplified test. Instead of calling echo, I actually want to run some more complicated scripts.

However, when I run this configuration, it throws with the following error:

 ==> /dev/null <==
 tail: cannot open 'echo "test"' for reading: No such file or directory

Not sure where tail has come from and how it can be fixed. Looking at this, it should work. If I remove command, it works fine. Any help will be appriciated.

UPDATE: DockerFile doesn't do anything other than installing dotnet and building my library.

UPDATE2: The base docker file is:

    FROM mcr.microsoft.com/dotnet/aspnet:6.0 AS base
    WORKDIR /app
    EXPOSE 80
    EXPOSE 443

    FROM mcr.microsoft.com/dotnet/sdk:6.0 AS build
    WORKDIR /src
    # restore
    COPY ["MyTests/MyTests.csproj", "MyTests/"]
    RUN dotnet restore "MyTests/MyTests.csproj"
    # build
    COPY . .
    WORKDIR "/src/MyTests"
    RUN dotnet build "MyTests.csproj" -c Release -o /app/build

Adding suggested ENTRYPOINT ["/bin/bash", "-c"] to the end of above docker file doesn't help. note: I'm novice in docker and docker-compose.

UPDATE3: Adding ENTRYPOINT ["tail", "-f", "/dev/null"] to the end of docketfile and changing how I call command to command: [echo, test], doesn't help. In general, I'm curious what's the deal with tail? Why it appears in this case at all?

NOTE: for the context, I want to configure integration test that will work with few containers, so instead of echo .., I want to run dotnet test .. for my integration tests

UPDATE4: The below configuration:

    FROM mcr.microsoft.com/dotnet/sdk:6.0 AS build
    WORKDIR /src
    EXPOSE 80
    EXPOSE 443
    # restore
    COPY ["MyTests/MyTests.csproj", "MyTests/"]
    RUN dotnet restore "MyTests/MyTests.csproj"
    # build
    COPY . .
    WORKDIR "/src/MyTests"
    RUN dotnet build "MyTests.csproj" -c Release -o /app/build

    ENTRYPOINT ["/bin/bash"]

works well if I run it from cmd locally:

    %SomePath%\Demo>docker build -f MyTests/Dockerfile  -t mytest .
    [+] Building 0.3s (12/12) FINISHED
     => [internal] load build definition from Dockerfile
     => => transferring dockerfile: 32B
     => [internal] load .dockerignore
     => => transferring context: 35B
     => [internal] load metadata for mcr.microsoft.com/dotnet/sdk:6.0
     => [1/7] FROM mcr.microsoft.com/dotnet/sdk:6.0
     => [internal] load build context
     => => transferring context: 2.00kB
     => CACHED [2/7] WORKDIR /src 
     => CACHED [3/7] COPY [MyTests/MyTests.csproj, MyTests/] 
     => CACHED [4/7] RUN dotnet restore "MyTests/MyTests.csproj"
     => CACHED [5/7] COPY . .
     => CACHED [6/7] WORKDIR /src/MyTests
     => CACHED [7/7] RUN dotnet build "MyTests.csproj" -c Release -o /app/build
     => exporting to image
     => => exporting layers
     => => writing image sha256:9c...
     => => naming to docker.io/library/mytest

    %SomePath%\Demo>docker run -it mytest
    root@999afef78716:/src/MyTests# ls
    MyTests.csproj  ApiTests.cs  Properties  obj

So, it looks like the problem is only about how to call it correctly from docker-compose configuration. I've also tried setting the below options

..
image: ${DOCKER_REGISTRY-}mytests
stdin_open: true # docker run -i
tty: true        # docker run -t
..

with no luck.

UPDATE5: I've tried to simplify all logic I have to these 2 files with new console application:

Dockerfile:

 FROM alpine:3.14
 WORKDIR "/src"
 CMD ["/bin/bash"]

 # same behavior if I use `CMD ["/bin/sh"]`

docker-compose:

version: '3.4'

services:
  consoleappdocker:
    image: ${DOCKER_REGISTRY-}consoleappdocker
    build:
      context: .
      dockerfile: ConsoleAppDocker/Dockerfile
    container_name: "consoleappdocker"
    command: ["/bin/bash", "-c", "echo test"]

that still fails with tail: invalid number 'echo test' error, however I just noticed this output:

 docker ps -a  --no-trunc
 CONTAINER ID    IMAGE                  COMMAND                                        CREATED         STATUS                     PORTS     NAMES
 %id%            consoleappdocker:dev   "tail -f /dev/null /bin/bash -c 'echo test'"   7 minutes ago   Exited (1) 7 minutes ago             consoleappdocker

so it looks like @VonC is right, however I have no ideas where this tail part has been initially added

UPDATE6 : Apparently the tail part is added by visual studio that I used to build and run my application, I found it in the logs:

    docker-compose  -f "%PATH%\docker-compose.yml" -f "%PATH%\docker-compose.override.yml" -f "%PATH%\obj\Docker\docker-compose.vs.debug.g.yml" -p dockercompose14997374556887134345 --ansi never --profile "*" config
    name: dockercompose14997374556887134345
    services:
      consoleappdocker:
        build:
          context: %PATH%
          dockerfile: ConsoleAppDocker/Dockerfile
          labels:
            com.microsoft.created-by: visual-studio
            com.microsoft.visual-studio.project-name: ConsoleAppDocker
        command:
        - /bin/bash
        - -c
        - echo test
        container_name: consoletest
        entrypoint:
        - tail
        - -f
        - /dev/null
        environment:
    ..
        image: consoleappdocker:dev
        labels:
    ..
        networks:
          default: null
        tty: true
        volumes:
    ..
    networks:
      default:
        name: dockercompose14997374556887134345_default
    docker-compose  -f "%PATH%\docker-compose.yml" -f "%PATH%\docker-compose.override.yml" -f "%PATH%\obj\Docker\docker-compose.vs.debug.g.yml" -p dockercompose14997374556887134345 --ansi never build

quite unexpected case, but I think it's more or less clear what to do next